Enkosi ngokundwendwela indalo.com. Usebenzisa uguqulelo lwebrawuza enenkxaso encinci yeCSS. Ukufumana awona mava angcono, sicebisa ukuba usebenzise isikhangeli esihlaziyiweyo (okanye ucime imo ehambelanayo kwi-Internet Explorer). Okwangoku, ukuqinisekisa inkxaso eqhubekayo, sibonisa indawo ngaphandle kwezitayela kunye neJavaScript.
Sichaza umphumo ophawulekayo we-photovoltaic kwi-YBa2Cu3O6.96 (YBCO) i-ceramic phakathi kwe-50 kunye ne-300 K eyenziwa yi-blue-laser illumination, ehambelana ngqo ne-superconductivity ye-YBCO kunye ne-YBCO-metallic electrode interface. Kukho ukuguqulwa kwe-polarity kwi-voltage yesiphaluka evulekileyo i-Voc kunye ne-short circuit yangoku i-Isc xa i-YBCO idlula kwinguqu ukusuka kwi-superconducting ukuya kwi-resistive state. Sibonisa ukuba kukho amandla ombane ngaphaya kwe-superconductor-eqhelekileyo ujongano lwentsimbi, olubonelela ngamandla okwahlula iperi ye-electron-induced electron-hole. Olu jongano olunokubakho luqondisa ukusuka kwi-YBCO ukuya kwi-electrode yentsimbi xa i-YBCO i-superconducting kwaye itshintshela kwelinye icala xa i-YBCO iba yi-nonsuperconducting. Imvelaphi yezinto ezinokuthi zihambelane ngokukhawuleza kunye nefuthe elisondeleyo kwi-metal-superconductor interface xa i-YBCO i-superconducting kwaye ixabiso layo liqikelelwa ukuba yi- ~ 10-8 mV kwi-50 K nge-laser intensity ye-502 mW / cm2. Ukudityaniswa kohlobo lwe-p-uhlobo lwe-YBCO kwimeko eqhelekileyo kunye nohlobo lwe-n-uhlobo lwe-Ag-paste yenza i-quasi-pn junction ejongene nokuziphatha kwe-photovoltaic ye-YBCO ceramics kumaqondo okushisa aphezulu. Iziphumo zethu zinokuvula indlela eya kwizicelo ezitsha zezixhobo ze-photon-elektroniki kwaye zikhanyise ngakumbi malunga nefuthe elisondeleyo kwi-interface ye-superconductor-metal.
Umbane owenziwe ngefoto kwii-superconductors zobushushu obuphezulu uxelwe kwasekuqaleni kweminyaka yee-1990 kwaye waphandwa kakhulu ukusukela ngoko, ukanti ubume bayo kunye nendlela asebenza ngayo azinzanga 1,2,3,4,5. I-YBa2Cu3O7-δ (YBCO) iifilimu ezibhityileyo6,7,8, ngokukodwa, zifundiswa ngokunzulu ngendlela ye-photovoltaic (PV) yeseli ngenxa ye-gap yayo yamandla ehlengahlengiswayo9,10,11,12,13. Nangona kunjalo, ukuchasana okuphezulu kwe-substrate kuhlala kukhokelela ekusebenzeni okuphantsi kokuguqulwa kwesixhobo kwaye imaski iipropathi eziphambili zePV zeYBCO8. Apha sichaza umphumo ophawulekayo we-photovoltaic owenziwe yi-blue-laser (λ = 450 nm) ukukhanyisa kwi-YBa2Cu3O6.96 (YBCO) i-ceramic phakathi kwe-50 kunye ne-300 K (Tc ~ 90 K). Sibonisa ukuba umphumo we-PV uhambelana ngqo ne-superconductivity ye-YBCO kunye nohlobo lwe-YBCO-metallic electrode interface. Kukho ukuguqulwa kwe-polarity kwi-voltage yesiphaluka evulekileyo i-Voc kunye ne-short circuit yangoku i-Isc xa i-YBCO idlula kwinguqu ukusuka kwisigaba se-superconducting ukuya kwisimo esichasayo. Kucetywa ukuba kubekho amandla ombane ngapha kwe-superconductor-eqhelekileyo ujongano lwesinyithi, olubonelela ngamandla okwahlula iperi ye-electron-induced electron-hole. Olu jongano olunokubakho luqondisa ukusuka kwi-YBCO ukuya kwi-electrode yentsimbi xa i-YBCO i-superconducting kwaye itshintshela kwelinye icala xa isampuli iba nonsuperconducting. Imvelaphi yesakhono sinokunxulunyaniswa ngokwemvelo kunye nefuthe elisondeleyo14,15,16,17 kwi-metal-superconductor interface xa i-YBCO i-superconducting kwaye ixabiso layo liqikelelwa ukuba yi- ~ 10-8 mV kwi-50 K nge-laser intensity ye-502 mW. /cm2. Ukudityaniswa kohlobo lwe-p-mathiriyeli ye-YBCO kwimeko yesiqhelo kunye nohlobo lwe-n-uhlobo lwe-Ag-paste iifom, mhlawumbi, i-quasi-pn junction ejongene nokuziphatha kwe-PV yeeseramics ze-YBCO kumaqondo aphezulu obushushu. Uqwalaselo lwethu lukhanyisa ngakumbi imvelaphi yesiphumo se-PV kubushushu obuphezulu be-YBCO ceramics kwaye ivule indlela yokusetyenziswa kwayo kwizixhobo ze-optoelectronic ezifana ne-passive passive detector etc.
Umzobo we-1a-c ubonisa ukuba iimpawu ze-IV ze-YBCO zesampulu ze-ceramic kwi-50 K. Ngaphandle kokukhanya kokukhanya, i-voltage kwisampuli ihlala kwi-zero ngokutshintsha kwangoku, njengoko kunokulindeleka kwi-superconducting material. Umphumo ocacileyo we-photovoltaic ubonakala xa i-laser beam iqondiswe kwi-cathode (umzobo 1a): i-curves ye-IV ehambelana ne-I-axis ihamba phantsi ngokunyuka kwe-laser. Kucacile ukuba kukho amandla ombane angeyonyani abangelwa yifoto nangaphandle kwayo nayiphi na yangoku (ehlala ibizwa ngokuba yi-open circuit voltage Voc). I-slope ye-zero ye-curve ye-IV ibonisa ukuba isampuli i-superconducting phantsi kokukhanya kwe-laser.
(a–c) kunye nama-300 K (e–g). Amaxabiso e-V(I) afunyenwe ngokutshayela umsinga ukusuka ku-−10 mA ukuya kwi +10 mA kwivacuum. Inxalenye kuphela yedatha yovavanyo inikezelwe ngenxa yokucaca. a, Iimpawu zangoku ze-voltage ze-YBCO ezilinganiswa ngendawo yelaser ebekwe kwi-cathode (i). Zonke iigophe ze-IV ziyimigca ethe tye ethe tye ebonisa ukuba isampuli iseyi-superconducting kunye ne-laser irradiation. Ijiko lehla ngokunyuka kokuqina kwelaser, ebonisa ukuba kukho amandla angalunganga (i-Voc) phakathi kwee-voltage ezimbini ezikhokelela nokuba ngu-zero wangoku. Iingqungquthela ze-IV zihlala zingatshintshi xa i-laser iqondiswe kwiziko lesampuli kwi-ether 50 K (b) okanye i-300 K (f). Umgca othe tye uhambela phezulu njengoko i-anode ikhanya (c). Imodeli eqingqiweyo yentsimbi-superconductor junction kwi-50 K iboniswe kwi-d. Iimpawu zangoku ze-voltage zemo yesiqhelo ye-YBCO kwi-300 K elinganiswe nge-laser beam ekhonjwe kwi-cathode kunye ne-anode inikwe kwi-e kunye ne-g ngokulandelelanayo. Ngokuchasene neziphumo kwi-50 K, i-slope engekho zero yemigca ethe tye ibonisa ukuba i-YBCO ikwimeko eqhelekileyo; amaxabiso eVoc ayahluka ngokukhanya kokukhanya kwicala elichaseneyo, ebonisa indlela yokwahlula intlawulo eyahlukileyo. Ulwakhiwo olunokwenzeka lojongano kwi-300 K lubonisiwe kwi-hj Umfanekiso wokwenyani wesampulu enesikhokelo.
I-YBCO eneoksijini etyebileyo kwimo ye-superconducting inokufunxa phantse i-spectrum epheleleyo yokukhanya kwelanga ngenxa yesikhewu samandla esincinci kakhulu (Umzekelo) i-9,10, ngokwenza njalo idale izibini ze-electron-hole (e-h). Ukuvelisa amandla ombane wesekethe evulekileyo iVoc ngokufunxwa kweefotoni, kuyafuneka ukwahlula ngokwesithuba iiperi ze-eh ezenziwe ngeefoto phambi kokuba kudityaniswe kwakhona18. I-Voc engeyiyo, inxulumene ne-cathode kunye ne-anode njengoko kubonisiwe kwi-Fig. 1i, icebisa ukuba kukho amandla ombane kwi-interface ye-metal-superconductor, etshayela i-electron kwi-anode kunye nemingxuma kwi-cathode. Ukuba oku kunjalo, kufuneka kwakhona kubekho ukukhomba okunokwenzeka ukusuka kwi-superconductor ukuya kwi-electrode yensimbi kwi-anode. Ngenxa yoko, i-Voc elungileyo iya kufumaneka ukuba indawo yesampulu ekufutshane ne-anode iyakhanyiswa. Ngaphaya koko, akufuneki kubekho imitha yombane eyenziwe ngefoto xa indawo yelaser isalathwa kwiindawo ezikude kwii-electrode. Ngokuqinisekileyo kunjalo njengoko kunokubonwa kumfanekiso 1b,c!.
Xa indawo yokukhanya isuka kwi-cathode electrode ukuya kumbindi wesampuli (malunga ne-1.25 mm ngaphandle kwe-interfaces), akukho ntlukwano ye-IV curves kwaye akukho Voc inokubonwa ngokunyuka kwe-laser kwixabiso eliphezulu elikhoyo (Umfanekiso 1b) . Ngokwemvelo, esi siphumo singabalelwa kubomi obunqamlekileyo bokuthwala iifoto kunye nokungabikho kwamandla okwahlukana kwisampuli. Izibini ze-electron-hole zingadalwa nanini na xa isampuli ikhanyisa, kodwa ininzi ye-e-h izibini ziya kutshabalalisa kwaye akukho siphumo se-photovoltaic sibonwa ukuba indawo ye-laser iwela kwiindawo ezikude kuyo nayiphi na i-electrode. Ukuhambisa indawo ye-laser kwi-anode electrodes, i-IV curves parallel to I-axis ihambela phezulu ngokunyuka kwe-laser intensity (Fig. 1c). Intsimi yombane eyakhelweyo efanayo ikhona kwi-metal-superconductor junction kwi-anode. Nangona kunjalo, i-electrode yensimbi idibanisa kwisikhokelo esilungileyo senkqubo yokuvavanya ngeli xesha. Imingxuma eveliswa yilaser ityhalelwa kwi-anode lead kwaye ke iVoc entle iyabonwa. Iziphumo ezithiwe thaca apha zibonelela ngobungqina obunamandla bokuba kukho ngokwenene ujongano olunokukhomba ukusuka kwi-superconductor ukuya kwi-electrode yesinyithi.
Impembelelo ye-Photovoltaic kwi-YBa2Cu3O6.96 i-ceramics kwi-300 K iboniswe kwi-Fig. 1e-g. Ngaphandle kokukhanya kokukhanya, ijika le-IV lesampulu ngumgca othe ngqo owela imvelaphi. Lo mgca othe ngqo uhambela phezulu uhambelane nowokuqala ngokunyuka kwe-laser intensity irradiating kwi-cathode lead (Umfanekiso 1e). Kukho iimeko ezimbini zokukhawulela umdla kwisixhobo se-photovoltaic. Ubume besiphaluka esifutshane senzeka xa i-V = 0. I-current kule meko ibizwa ngokuba yi-short circuit current (Isc). Imeko yesibini yokukhawulela yimeko ye-open-circuit (Voc) eyenzeka xa i-R→∞ okanye i-current ingu-zero. Umzobo we-1e ubonisa ngokucacileyo ukuba i-Voc ilungile kwaye iyanda ngokunyuka kokukhanya kokukhanya, ngokuchasene nesiphumo esifunyenwe kwi-50 K; ngelixa i-Isc engathandekiyo ibonwa ngokunyuka kubukhulu ngokukhanya kokukhanya, ukuziphatha okuqhelekileyo kweeseli eziqhelekileyo zelanga.
Ngokufanayo, xa i-laser beam ibonakaliswe kwiindawo ezikude kwi-electrodes, i-V (I) ijika izimeleyo kwi-laser intensity kwaye akukho mphumela we-photovoltaic wabonakala (Umfanekiso 1f). Ngokufana nokulinganisa kwi-50 K, ii-curves ze-IV zihambela kwicala elichaseneyo njengoko i-anode electrode i-irradiated (Umfanekiso 1g). Zonke ezi ziphumo ezifunyenwe kule nkqubo yokuncamathisela ye-YBCO-Ag kwi-300 K enelaser irradiated kwiindawo ezahlukeneyo zesampulu iyahambelana ne-interface enokubakho echaseneyo nebonwa kwi-50 K.
Uninzi elekhtroni ukujiya kwiCooper ngababini superconducting YBCO ngaphantsi iqondo lotshintsho Tc. Ngelixa kwi-electrode yensimbi, zonke ii-electron zihlala zikwimo enye. Kukho ingxinano enkulu kuzo zombini ii-electron isinye kunye izibini Cooper kwindawo ekufutshane ujongano metal-superconductor. Uninzi lwee-electron zesinye kwi-metallic material ziya kusasazeka kummandla we-superconductor, ngelixa uninzi lwabathwali bee-Cooper-izibini kummandla we-YBCO ziya kusasazwa kummandla wesinyithi. Njengoko ii-Cooper pairs ezithwele iintlawulo ezininzi kunye nokuba nokushukuma okukhulu kunee-electron zesinye zisasazeke ukusuka kwi-YBCO ukuya kummandla wesinyithi, ii-athom ezichajiwe kakuhle zishiywe ngasemva, okukhokelela kwintsimi yombane kwindawo yentlawulo yesithuba. Isalathiso salo mmandla wombane siboniswe kumzobo wesikimu Umfanekiso 1d. Isehlo sokukhanya kwefoton kufutshane nommandla wentlawulo yesithuba kunokudala izibini eziya kwahlulwa kwaye zitshayelwe zivelisa i-photocurrent kwicala elingasemva. Ngokukhawuleza ukuba ii-electron ziphuma kwindawo yombane eyakhiweyo, zixutywa zibe ngazibini kwaye zigeleze kwenye i-electrode ngaphandle kokuchasana. Kule meko, i-Voc ichasene ne-polarity yangaphambili kwaye ibonisa ixabiso elibi xa i-laser beam ikhomba kwindawo ejikeleze i-electrode engalunganga. Ukusuka kwixabiso le-Voc, okunokwenzeka kulo lonke ujongano kunokuqikelelwa: umgama phakathi kwee-voltage ezimbini ezikhokelela kwi-d yi ~ 5 × 10−3 m, ubukhulu be-metal-superconductor interface, di, kufuneka bube ngumyalelo ofanayo wobukhulu. njengobude bokuhambelana kwe-YBCO superconductor (~1 nm)19,20, thatha ixabiso le-Voc = 0.03 mV, i-Vms enokwenzeka i-metal-superconductor interface ivavanywa ukuba ibe ~ 10−11 V kwi-50 K ngokuqina kwe-laser ye-502 mW/cm2, kusetyenziswa i-equation,
Sifuna ukugxininisa apha ukuba i-voltage eyenziwe ngefoto ayinakuchazwa ngefuthe lobushushu befoto. Kuye kwafunyaniswa ngovavanyo ukuba i-coefficient ye-Seebeck ye-superconductor YBCO yi-Ss = 021. I-coefficient ye-Seebeck yeengcingo ezikhokelayo zobhedu ikuluhlu lwe-SCu = 0.34-1.15 μV/K3. Ubushushu bocingo lobhedu kwindawo ye-laser bunokunyuswa ngexabiso elincinci le-0.06 K kunye ne-laser intensity ephezulu ekhoyo kwi-50 K. Oku kunokuvelisa amandla ombane we-thermoelectric we-6.9 × 10−8 V enemilinganiselo emithathu yobukhulu obuncinci kune iVoc efunyenwe kwiFig 1 (a). Kucacile ukuba umphumo we-thermoelectric umncinci kakhulu ukuchaza iziphumo zovavanyo. Ngapha koko, ukuguquguquka kwamaqondo obushushu ngenxa ye-laser irradiation kuya kunyamalala ngaphantsi komzuzu omnye ukuze igalelo elivela kwisiphumo sobushushu lingahoywa ngokukhuselekileyo.
Le mpembelelo ye-photovoltaic ye-YBCO kwiqondo lokushisa kwegumbi ibonisa ukuba indlela yokwahlula intlawulo eyahlukileyo ibandakanyeka apha. I-Superconducting YBCO kwimeko yesiqhelo yinto yohlobo lwe-p enemingxuma njenge-carrier carrier22,23, ngelixa i-metallic Ag-paste ineempawu ze-n-type material. Ngokufana ne-pn junctions, ukusasazwa kwee-electron kwi-paste yesilivere kunye nemingxuma kwi-YBCO ye-ceramic iya kwenza intsimi yombane yangaphakathi ekhomba kwi-YBCO ceramic kwi-interface (Fig. 1h). Yiyo le ntsimi yangaphakathi enika amandla okuhlula kwaye ikhokelela kwi-Voc enhle kunye ne-Isc engalunganga ye-YBCO-Ag inkqubo yokunamathisela kwiqondo lokushisa, njengoko kuboniswe kwi-Fig. Kungenjalo, i-Ag-YBCO inokwenza i-p-type Schottky junction ekwakhokelela kujongano olunokubakho olunobumbano olufanayo njengakwimodeli eboniswe ngasentla24.
Ukuphanda inkqubo ye-evolution eneenkcukacha yeempawu ze-photovoltaic ngexesha lokuguqulwa kwe-superconducting ye-YBCO, ii-curves ze-IV zesampuli kwi-80 K zilinganiswe nge-laser intensity ekhethiweyo ekhanyisa kwi-cathode electrode (Umfanekiso 2). Ngaphandle kwe-laser irradiation, i-voltage kwi-sample igcina i-zero kungakhathaliseki ukuba ikhoyo ngoku, ibonisa i-superconducting state yesampuli kwi-80 K (Umfanekiso 2a). Ngokufana nedatha efunyenwe kwi-50 K, i-IV i-curves ehambelana ne-I-axis ihamba phantsi ngokunyuka kwe-laser intensity de kufike ixabiso elibalulekileyo lePc. Ngaphezulu kweli nqanaba elibalulekileyo le-laser (Pc), i-superconductor idlula kwinguqu ukusuka kwinqanaba eliphezulu ukuya kwisigaba sokumelana; i-voltage iqala ukunyuka ngoku ngoku ngenxa yokubonakala kokuchasana kwi-superconductor. Ngenxa yoko, i-curve ye-IV iqala ukunqumla kunye ne-I-axis kunye ne-V-axis ekhokelela kwi-Voc embi kunye ne-Isc enhle ekuqaleni. Ngoku isampuli ibonakala ikwimeko ekhethekileyo apho i-polarity ye-Voc kunye ne-Isc inomdla kakhulu ekukhanyeni kokukhanya; ngokunyuka okuncinci kakhulu ekukhanyeni kokukhanya i-Isc iguqulwa ukusuka kwi-positive ukuya kwi-negative kunye ne-Voc ukusuka kwi-negative ukuya kwixabiso elihle, ukudlula imvelaphi (uvakalelo oluphezulu lweempawu ze-photovoltaic, ngokukodwa ixabiso le-Isc, ukukhanya kokukhanya kunokubonwa ngokucacileyo kwi-Fig. 2b). Kwi-laser intensity ephezulu ekhoyo, i-IV curves inenjongo yokuhambelana enye kwenye, ebonisa imeko eqhelekileyo yesampuli ye-YBCO.
Iziko le-laser spotting libekwe malunga ne-cathode electrode (jonga umfanekiso we-1i). a, iigophe ze-IV ze-YBCO ezifakwe kwi-laser intensities ezahlukeneyo. b (phezulu), iLaser intensity dependence of open circuit voltage Voc and short circuit current current Isc. Amaxabiso e-Isc awanakufunyanwa kukukhanya okuphantsi (<110 mW / cm2) kuba ii-curves ze-IV zihambelana ne-I-axis xa isampuli ikwimeko ye-superconducting. b (ezantsi), ukuchasana ngokwahlukileyo njengomsebenzi we-laser intensity.
Ukuxhomekeka kwe-laser ye-laser ye-Voc kunye ne-Isc kwi-80 K kuboniswe kwi-Fig. 2b (phezulu). Iimpawu ze-photovoltaic zinokuxoxwa kwimimandla emithathu yokukhanya kokukhanya. Ummandla wokuqala uphakathi kwe-0 kunye ne-Pc, apho i-YBCO i-superconducting, i-Voc i-negative kwaye iyancipha (ixabiso elipheleleyo lokunyuka) kunye nokukhanya kokukhanya kunye nokufikelela ubuncinane kwi-Pc. Ummandla wesibini usuka kwi-Pc ukuya kobunye ubunzulu obunzulu be-P0, apho i-Voc inyuka ngelixa i-Isc iyancipha ngokunyuka kokukhanya kokukhanya kwaye zombini ifikelela kwi-zero kwi-P0. Ummandla wesithathu ungaphezulu kwe-P0 kude kube yimeko eqhelekileyo ye-YBCO ifikelelwe. Nangona zombini i-Voc kunye ne-Isc zihluka ngokukhanya kokukhanya ngendlela efanayo nakwingingqi yesi-2, zinepolarity echaseneyo ngaphezulu koxinzelelo olubalulekileyo P0. Ukubaluleka kwe-P0 kulele ekubeni akukho siphumo se-photovoltaic kwaye indlela yokwahlula intlawulo itshintsha ngokusemgangathweni kule ndawo. Isampulu ye-YBCO iba yi-non-superconducting kolu luhlu lobunzima bokukhanya kodwa imeko eqhelekileyo engekafikelelwa.
Ngokucacileyo, iimpawu ze-photovoltaic zenkqubo zihambelana ngokusondeleyo ne-superconductivity ye-YBCO kunye ne-superconducting transition yayo. Ukumelana nokwahlukana, i-dV / dI, ye-YBCO iboniswe kwi-Fig. 2b (ezantsi) njengomsebenzi we-laser intensity. Njengoko bekutshiwo ngaphambili, i-built-in amandla ombane kwi-interface ngenxa yamanqaku e-Cooper diffusion ukusuka kwi-superconductor ukuya kwintsimbi. Ngokufanayo naloo nto ibonwe kwi-50 K, umphumo we-photovoltaic uphuculwe ngokunyuka kwe-laser intensity ukusuka kwi-0 ukuya kwi-Pc. Xa ubukhulu belaser bufikelela kwixabiso elincinci ngaphezu kwePc, ijika le-IV liqala ukuthambeka kwaye ukuchasana kwesampulu kuqala ukubonakala, kodwa i-polarity ye-interface enokubakho ayitshintshi okwangoku. Impembelelo ye-optical excitation kwi-superconductivity iphandiwe kwindawo ebonakalayo okanye ekufutshane ne-IR. Nangona inkqubo esisiseko kukuqhekeza izibini ze-Cooper kunye nokutshabalalisa i-superconductivity25,26, kwezinye iimeko i-superconductivity transition ingaphuculwa27,28,29, izigaba ezitsha ze-superconductivity zinokuthi zenziwe30. Ukungabikho kwe-superconductivity kwi-Pc kunokubalelwa kwi-photo-induced pair breaking. Kwinqanaba le-P0, okunokwenzeka ngaphaya kojongano kuba ngu-zero, ebonisa ukuba uxinano lwentlawulo kumacala omabini ojongano lufikelela kwinqanaba elifanayo phantsi kobu bunzulu bokukhanya kokukhanya. Ukwanda ngakumbi koxinzelelo lwelaser kubangela ukuba izibini ezininzi ze-Cooper zitshatyalaliswe kwaye i-YBCO iguqulwa ngokuthe ngcembe ibe yinto yohlobo lwe-p. Endaweni ye-electron kunye ne-Cooper pair diffusion, inkalo yojongano ngoku imiselwe yi-electron kunye nokusasazwa komngxuma okukhokelela ekubuyiseleni ukuguqulwa kwe-polarity kwi-interface kwaye ngenxa yoko i-Voc enhle (thelekisa i-Fig.1d, h). Kwi-laser intensity ephezulu kakhulu, ukuchasana okungafaniyo kwe-YBCO kugcwele kwixabiso elihambelana nesimo esiqhelekileyo kwaye zombini i-Voc kunye ne-Isc zivame ukuhluka ngokuhambelana ne-laser intensity (Fig. 2b). Olu qwalaselo lubonisa ukuba i-laser irradiation kwisimo esiqhelekileyo se-YBCO ayisayi kutshintsha i-resistivity yayo kunye ne-interface ye-superconductor-metal interface kodwa yandisa kuphela ukuxinwa kwee-electron-hole pairs.
Ukuphanda umphumo weqondo lokushisa kwiipropati ze-photovoltaic, inkqubo ye-metal-superconductor yahlanjululwa kwi-cathode kunye ne-blue laser of intensity 502 mW / cm2. Iijika ze-IV ezifunyenwe kumaqondo okushisa akhethiweyo phakathi kwe-50 kunye ne-300 K zinikwe kwi-Fig. 3a. I-voltage yesiphaluka evulekileyo i-Voc, i-short circuit yangoku i-Isc kunye nokumelana nokwahlukana kunokufumaneka kula ma-curves e-IV kwaye iboniswe kwi-Fig. 3b. Ngaphandle kokukhanya kokukhanya, zonke iijika ze-IV ezilinganiswe kumaqondo okushisa ahlukeneyo adlula imvelaphi njengoko kulindelwe (i-inset of Fig. 3a). Iimpawu ze-IV zitshintsha kakhulu ngokunyuka kweqondo lokushisa xa inkqubo ikhanyiswa yi-laser beam eqinile (502 mW / cm2). Kubushushu obuphantsi iigophe ze-IV ziyimigca ethe tye ehambelana ne-I-axis enexabiso elibi le-Voc. Le ngqungquthela inyuka inyuka ngokunyuka kweqondo lokushisa kwaye ngokuthe ngcembe ijika ibe ngumgca kunye ne-nonzero slope kwiqondo lokushisa elibalulekileyo Tcp (Umfanekiso 3a (phezulu)). Kubonakala ngathi zonke iigophe zeempawu ze-IV zijikeleza kwindawo ethile kwiquadrant yesithathu. I-Voc inyuka ukusuka kwixabiso elingalunganga ukuya kwelilungileyo ngelixa i-Isc iyancipha ukusuka kwi-positive ukuya kwixabiso elingalunganga. Ngaphezulu kweqondo lokushisa lokutshintsha kwe-superconducting yokuqala ye-Tc ye-YBCO, ijika le-IV litshintsha ngokungafaniyo nobushushu (ezantsi kweFig. 3a). Okokuqala, iziko lokujikeleza leegophe ze-IV liya kwi-quadrant yokuqala. Okwesibini, iVoc igcina iyancipha kwaye i-Isc ikhula ngokunyuka kwamaqondo obushushu (phezulu kweFig. 3b). Okwesithathu, i-slope ye-IV curves inyuka ngokuhambelana nokushisa okubangelwa umlinganiso wokushisa ochanekileyo wokumelana ne-YBCO (ezantsi kwe-Fig 3b).
Ukuxhomekeka kobushushu beempawu ze-photovoltaic ze-YBCO-Ag inkqubo yokunamathisela phantsi kwe-502 mW / cm2 yokukhanya kwe-laser.
Iziko le-laser spotting libekwe malunga ne-cathode electrode (jonga umfanekiso we-1i). a, iijika ze-IV ezifunyenwe kwi-50 ukuya kwi-90 K (phezulu) kunye ne-100 ukuya kwi-300 K (ezantsi) kunye nokunyuka kweqondo lokushisa kwe-5 K kunye ne-20 K, ngokulandelanayo. Iseti a ibonisa iimpawu ze-IV kumaqondo obushushu amaninzi ebumnyameni. Zonke iigophe ziwela indawo yemvelaphi. b, i-voltage yesiphaluka evulekileyo i-Voc kunye ne-short circuit current i-Isc (phezulu) kunye nokumelana nokwahlukana, i-dV / dI, ye-YBCO (ezantsi) njengomsebenzi wokushisa. Ubushushu be-zero bokumelana ne-superconducting transition ye-Tcp ayinikwanga kuba isondele kakhulu kwi-Tc0.
Ukushisa okuthathu okubalulekileyo kunokubonwa kwi-Fig. 3b: Tcp, ngasentla apho i-YBCO iba yi-non-superconducting; I-Tc0, apho zombini i-Voc kunye ne-Isc ziba ngu-zero kunye ne-Tc, iqondo lokuqala lokutshintsha kwe-superconducting ye-YBCO ngaphandle kwe-laser irradiation. Ngaphantsi kwe-Tcp ~ 55 K, i-laser irradiated YBCO ikwimo ephezulu ye-superconducting kunye noxinzelelo oluphezulu lwee-Cooper pairs. Umphumo we-laser irradiation kukunciphisa ukushisa kwe-zero yokumelana ne-superconducting ukusuka kwi-89 K ukuya kwi-55 K (ezantsi kwe-Fig. 3b) ngokunciphisa i-Cooper pair concentration ngaphezu kokuvelisa i-photovoltaic voltage kunye nekhoyo ngoku. Ukwanda kwamaqondo obushushu ukwaphula phantsi izibini Cooper ekhokelela kwisakhono esisezantsi ujongano. Ngenxa yoko, ixabiso elipheleleyo leVoc liya kuba lincinci, nangona ukuqina okufanayo kokukhanya kwelaser kusetyenziswa. Ujongano olunokubakho luya kuba luncinci kwaye lube luncinci ngokunyuka okuthe kratya kwiqondo lobushushu kwaye lufikelele kwi-zero kwi-Tc0. Akukho mphumela we-photovoltaic kule ndawo ekhethekileyo kuba akukho ntsimi yangaphakathi yokwahlula i-photo-induced electron-hole pairs. Ukuguqulwa kwepolarity okunokwenzeka kwenzeka ngaphezu kobu bushushu bubalulekileyo njengoko ingxinano yentlawulo yasimahla kwi-Ag paste inkulu kunoleyo ikwi-YBCO ethi ngokuthe ngcembe itshintshelwe emva kwisixhobo sohlobo lwe-p. Apha sifuna ukugxininisa ukuba ukuguqulwa kwe-polarity ye-Voc kunye ne-Isc kwenzeka ngokukhawuleza emva kwenguqu ye-zero yokumelana ne-superconducting, kungakhathaliseki ukuba yintoni imbangela yokuguquka. Olu qwalaselo lubonisa ngokucacileyo, ngokokuqala ngqa, ukuhambelana phakathi kwe-superconductivity kunye nemiphumo ye-photovoltaic ehambelana ne-metal-superconductor interface. Ubume bolu buchule kulo lonke i-superconductor-yesiqhelo ye-metal interface ibe lugqaliselo lophando kumashumi eminyaka adlulileyo kodwa mininzi imibuzo esalindele ukuphendulwa. Umlinganiselo wesiphumo se-photovoltaic unokubonisa ukuba yindlela esebenzayo yokuhlola iinkcukacha (njengamandla ayo kunye ne-polarity njl.) yale nto ibalulekileyo ebalulekileyo kwaye ngoko inika ukukhanya kwiqondo lokushisa eliphezulu le-superconducting proximity effect.
Ukunyuka okungaphezulu kobushushu ukusuka kwi-Tc0 ukuya kwi-Tc kukhokelela kugxininiso oluncinci lwezibini ze-Cooper kunye nokwandiswa kojongano olunokubakho kwaye ngenxa yoko enkulu iVoc. Kwi-Tc i-Cooper pair concentration iba ngu-zero kunye ne-build-in enokubakho kwi-interface ifikelela kwinqanaba eliphezulu, okukhokelela kwi-Voc ephezulu kunye ne-Isc encinci. Ukunyuka okukhawulezayo kweVoc kunye ne-Isc (ixabiso elipheleleyo) kolu luhlu lweqondo lokushisa luhambelana nokuguqulwa kwe-superconducting eyandisiweyo ukusuka kwi-ΔT ~ 3 K ukuya kwi-~34 K nge-laser irradiation of intensity 502 mW / cm2 (Fig. 3b). Kwiimeko eziqhelekileyo ezingentla kwe-Tc, i-voltage yesiphaluka evulekileyo i-Voc iyancipha ngeqondo lokushisa (phezulu kwi-Fig. 3b), efana nokuziphatha okucacileyo kweVoc kwiiseli eziqhelekileyo zelanga ezisekelwe kwi-pn junctions31,32,33. Nangona iqondo lotshintsho lweVoc eneqondo lobushushu (−dVoc/dT), elixhomekeke ngamandla kubushushu belaser, lincinci kakhulu kunelo leeseli zelanga eziqhelekileyo, umlinganiso wobushushu weVoc weYBCO-Ag usidibanisa unomyalelo wobukhulu ofanayo nalowo. yeeseli zelanga. Ukuvuza kwangoku kwe-pn junction yesixhobo esiqhelekileyo seseli yelanga kunyuka ngokunyuka kwamaqondo obushushu, okukhokelela ekunciphiseni kweVoc njengoko ubushushu bonyuka. Umgca we-IV we-curves obonwe kule nkqubo ye-Ag-superconductor, ngenxa yokuqala i-interface encinci kakhulu kwaye okwesibini i-back-to-back connection of the heterojunctions ezimbini, yenza kube nzima ukumisela ukuvuza kwangoku. Nangona kunjalo, iyathungelana kakhulu into yokuba ukuxhomekeka kobushushu obufanayo bokuvuza kwangoku kunoxanduva lokuziphatha kweVoc ebonwe kuvavanyo lwethu. Ngokwengcaciso, i-Isc yeyona nto ikhoyo ngoku efunekayo ukuvelisa i-voltage engalunganga yokuhlawula iVoc ukuze i-voltage iyonke ibe ngu-zero. Njengoko iqondo lobushushu lisanda, iVoc iba yincinci ukuze incinci okwangoku ifunekayo ukuvelisa amandla ombane angalunganga. Ngaphezu koko, ukuchasana kwe-YBCO kwandisa ngokuhambelana nokushisa ngaphezu kwe-Tc (ezantsi kwe-Fig. 3b), ekwafaka isandla kwixabiso elincinci elipheleleyo le-Isc kumaqondo aphezulu.
Qaphela ukuba iziphumo ezinikwe kwiFig 2,3 zifumaneka ngelaser irradiating kwindawo ejikeleze i-cathode electrode. Imilinganiselo iphinde iphindwe nge-laser spot ebekwe kwi-anode kunye neempawu ze-IV ezifanayo kunye neempawu ze-photovoltaic ziye zabonwa ngaphandle kokuba i-polarity ye-Voc kunye ne-Isc iguqulwe kule meko. Zonke ezi datha zikhokelela kwindlela yokwenza i-photovoltaic effect, ehambelana ngokusondeleyo ne-superconductor-metal interface.
Isishwankathelo, iimpawu ze-IV ze-laser irradiated superconducting YBCO-Ag inkqubo yokunamathisela ziye zalinganiswa njengemisebenzi yokushisa kunye nokuqina kwe-laser. Isiphumo esiphawulekayo se-photovoltaic siye sabonwa kwiqondo lokushisa ukusuka kwi-50 ukuya kwi-300 K. Kufunyaniswa ukuba iimpawu ze-photovoltaic zihambelana kakhulu ne-superconductivity ye-YBCO ceramics. Ukuguqulwa kwe-polarity ye-Voc kunye ne-Isc kwenzeka ngokukhawuleza emva kwe-photo-induced superconducting kwi-non-superconducting transition. Ukuxhomekeka kobushushu be-Voc kunye ne-Isc elinganiswe kukuqina kwe-laser esisigxina kubonisa kwakhona ukuguqulwa okucacileyo kwe-polarity kwiqondo lobushushu elibalulekileyo ngasentla apho isampuli ikwazi ukumelana. Ngokufumana indawo yelaser kwindawo eyahlukileyo yesampulu, sibonisa ukuba kukho amandla ombane kuwo wonke ujongano, nto leyo ebonelela ngamandla okwahlula iiperi ze-electron-induced electron-hole. Olu jongano olunokubakho luqondisa ukusuka kwi-YBCO ukuya kwi-electrode yentsimbi xa i-YBCO i-superconducting kwaye itshintshela kwelinye icala xa isampuli iba nonsuperconducting. Imvelaphi yesakhono sinokunxulunyaniswa ngokwemvelo nesiphumo sokusondela kwi-metal-superconductor interface xa i-YBCO i-superconducting kwaye iqikelelwa ukuba yi- ~ 10-8 mV kwi-50 K nge-laser intensity ye-502 mW / cm2. Ukuqhagamshelana nohlobo lwe-p-uhlobo lwe-YBCO kwimeko eqhelekileyo kunye nohlobo lwe-n-uhlobo lwe-Ag-paste yenza i-quasi-pn junction ejongene nokuziphatha kwe-photovoltaic ye-YBCO ceramics kumaqondo aphezulu okushisa. Oku kuqwalaselwe apha ngasentla kukhanyisela isiphumo se-PV kwiqondo eliphezulu lobushushu obuphezulu be-YBCO ceramics kunye nokuvula indlela eya kwizicelo ezitsha kwizixhobo ze-optoelectronic ezifana ne-fast passive light detector kunye ne-photon detector enye.
Uvavanyo lwesiphumo se-photovoltaic lwenziwa kwisampulu ye-ceramic ye-YBCO ye-0.52 mm ubukhulu kunye ne-8.64 × 2.26 mm2 imilo yoxande kwaye yakhanyiswa yi-laser eqhubekayo yamaza eluhlaza okwesibhakabhaka (λ = 450 nm) kunye nobukhulu bendawo ye-laser ye-1.25 mm kwi-radius. Ukusebenzisa ubuninzi kunokuba isampuli yefilimu encinci isenza ukuba sifunde iimpawu ze-photovoltaic ze-superconductor ngaphandle kokujongana nempembelelo enzima ye-substrate6,7. Ngaphezu koko, imathiriyeli eninzi inokuba luncedo kwinkqubo yayo yokulungiselela elula kunye neendleko eziphantsi. Iingcingo zobhedu ezikhokelayo zidibene kwisampuli ye-YBCO kunye ne-paste yesilivere eyenza i-electrode ezine ezijikelezayo malunga ne-1 mm ububanzi. Umgama phakathi kwee-electrode ezimbini zombane malunga ne-5 mm. Iimpawu ze-IV zesampulu zilinganiswe kusetyenziswa isampuli yemagnetometer yokungcangcazela (i-VersaLab, i-Quantum Design) enefestile yekristale ye-quartz. Indlela esemgangathweni yocingo olune yasetyenziswa ukufumana iigophe ze-IV. Izikhundla ezihambelanayo ze-electrodes kunye nebala le-laser ziboniswe kuMzobo 1i.
Indlela yokucaphula eli nqaku: Yang, F. et al. Imvelaphi yesiphumo se-photovoltaic kwi-superconducting YBa2Cu3O6.96 ceramics. Sci. Rep. 5, 11504; doi: 10.1038/srep11504 (2015).
Chang, CL, Kleinhammes, A., Moulton, WG & Testardi, LR Symmetry-inqatshelwe i-laser-induced voltages kwi-YBa2Cu3O7. I-Phys. Umfundisi B 41, 11564–11567 (1990).
Kwok, HS, Zheng, JP & Dong, SY Imvelaphi yesiginali ye-photovoltaic engaqhelekanga kwi-Y-Ba-Cu-O. I-Phys. Umfundisi B 43, 6270-6272 (1991).
Wang, LP, Lin, JL, Feng, QR & Wang, GW Umlinganiselo we-laser-induced voltages of superconducting Bi-Sr-Ca-Cu-O. I-Phys. Umfundisi B 46, 5773–5776 (1992).
Tate, KL, et al. I-voltages ye-laser-induced transient kwiifilimu zobushushu begumbi YBa2Cu3O7-x. J. Appl. I-Phys. 67, 4375–4376 (1990).
Kwok, HS & Zheng, JP Anomalous photovoltaic impendulo kwiYBa2Cu3O7. I-Phys. Umfundisi B 46, 3692–3695 (1992).
I-Muraoka, Y., i-Muramatsu, T., Yamaura, J. & Hiroi, Z. Inaliti yomngxuma wokuhambisa ifoto eyenziwe kwi-YBa2Cu3O7−x kwi-oxide heterostructure. Appl. I-Phys. Lett. 85, 2950-2952 (2004).
Asakura, D. et al. Uphononongo lwe-Photoemission ye-YBa2Cu3Oy iifilimu ezincinci eziphantsi kokukhanya kokukhanya. I-Phys. UMfundisi Lett. 93, 247006 (2004).
Yang, F. et al. Impembelelo ye-Photovoltaic ye-YBa2Cu3O7-δ/SrTiO3 :I-Nb heterojunction efakwe kwi-oksijeni eyahlukileyo yoxinzelelo oluyinxenye. Mater. Lett. 130, 51-53 (2014).
Aminov, BA et al. Ulwakhiwo lweGap ezimbini kwiYb (Y) Ba2Cu3O7-x iikristale enye. J. Supercond. 7, 361–365 (1994).
Kabanov, VV, Demsar, J., Podobnik, B. & Mihailovic, D. Quasiparticle relaxation dynamics in superconductors with different gap structures: Theory and experiments on YBa2Cu3O7-δ . I-Phys. Umfundisi B 59, 1497–1506 (1999).
Ilanga, JR, Xiong, CM, Zhang, YZ & Shen, BG Ukulungisa iipropati ze-YBa2Cu3O7-δ/SrTiO3 :Nb heterojunction. Appl. I-Phys. Lett. 87, 222501 (2005).
Kamarás, K., Porter, CD, Doss, MG, Herr, SL & Tanner, DB Excitonic absorption kunye ne-superconductivity kwi-YBa2Cu3O7-δ. I-Phys. UMfundisi Lett. 59, 919–922 (1987).
Yu, G., Heeger, AJ & Stucky, G. Transient photoinduced conductivity in semiconducting single crystals ye-YBa2Cu3O6.3: khangela i-photoinduced metallic state kunye ne-photoinduced superconductivity. I-Solid State Commun. 72, 345–349 (1989).
McMillan, imodeli ye-WL yeTunneling yesiphumo sokusondela kwe-superconducting. I-Phys. IsiTyhilelo 175, 537–542 (1968).
UGuéron, S. et al. Isiphumo sokusondela kwe-Superconducting esiphendlwe kwisikali sobude be-mesoscopic. I-Phys. UMfundisi Lett. 77, 3025-3028 (1996).
U-Annunziata, G. & Manske, D. Impembelelo yokusondela kunye ne-noncentrosymmetric superconductors. I-Phys. Umfundisi B 86, 17514 (2012).
Qu, FM kunye nabanye. Impembelelo enamandla yokusondela kwe-superconducting kwi-Pb-Bi2Te3 hybrid izakhiwo. Sci. Rep. 2, 339 (2012).
I-Chapin, i-DM, i-Fuller, i-CS & ne-Pearson, i-GL entsha ye-silicon pn junction photocell yokuguqula i-radiation yelanga ibe ngamandla ombane. J. App. I-Phys. 25, 676–677 (1954).
I-Tomimoto, i-K. Imiphumo yokungcola kwi-superconducting coherence length ubude kwi-Zn- okanye i-Ni-doped YBa2Cu3O6.9 i-crystals eyodwa. I-Phys. Umfundisi B 60, 114–117 (1999).
I-Ando, Y. & Segawa, K. Magnetoresistance ye-Untwinned YBa2Cu3Oy iikristale enye kuluhlu olubanzi lwe-doping: ukuxhomekeka okungaqhelekanga kwe-doping yobude bokuhambelana. I-Phys. UMfundisi Lett. 88, 167005 (2002).
Obertelli, SD & Cooper, JR Systematics kumandla we-thermoelectric aphezulu-T, i-oxides. I-Phys. Umfundisi B 46, 14928–14931, (1992).
Sugai, S. et al. I-Carrier-dependent-dependent momentum shift of the peak conherent kunye ne-LO phonon mode kwi-p-type high-Tc superconductors. I-Phys. Umfundisi B 68, 184504 (2003).
UNojima, T. et al. Ukunciphisa umngxuma kunye nokuqokelela i-electron kwiifilimu ezibhityileyo zeYBa2Cu3Oy zisebenzisa ubuchule be-electrochemical: Ubungqina bobume be-n-type metallic. I-Phys. Umfundisi B 84, 020502 (2011).
Tung, RT Ifiziksi kunye nekhemikhali yokuphakama komqobo weSchottky. Appl. I-Phys. Lett. 1, 011304 (2014).
Sai-Halasz, GA, Chi, CC, Denenstein, A. & Langenberg, DN Effects of Dynamic External Pair Breaking in Superconducting Films. I-Phys. UMfundisi Lett. 33, 215–219 (1974).
Nieva, G. et al. Ukomelezwa kwefoto ye-superconductivity. Appl. I-Phys. Lett. 60, 2159-2161 (1992).
Kudinov, VI et al. Ukuqhubekeka kwe-photoconductivity kwiifilimu ze-YBa2Cu3O6+x njengendlela yokwenza ifotodoping ukuya kwizigaba zetsimbi kunye ne-superconducting. I-Phys. Umfundisi B 14, 9017-9028 (1993).
UMankowsky, R. et al. I-nonlinear lattice dynamics njengesiseko sokuphucula i-superconductivity kwi-YBa2Cu3O6.5. Indalo 516, 71-74 (2014).
UFausti, D. et al. I-superconductivity eyenziwe ngokukhanya kwi-cuprate enemigca. Inzululwazi 331, 189-191 (2011).
El-Adawi, MK & Al-Nuaim, IA Ukuxhomekeka kokusebenza kweqondo lokushisa kwe-VOC kwiseli yelanga ngokumalunga nokusebenza kwayo ngendlela entsha. Ukukhutshwa kwetyuwa emanzini 209, 91-96 (2007).
Vernon, SM & Anderson, WA Iziphumo zobushushu kwi-Schottky-barrier silicon iiseli zelanga. Appl. I-Phys. Lett. 26, 707 (1975).
I-Katz, i-EA, i-Faiman, i-D. & ne-Tuladhar, i-SM Ukuxhomekeka kobushushu kwisixhobo se-photovoltaic parameters yeeseli zelanga ze-polymer-fullerene phantsi kweemeko zokusebenza. J. Appl. I-Phys. 90, 5343-5350 (2002).
Lo msebenzi uxhaswe yiNational Natural Science Foundation yaseChina (iSibonelelo esinguNombolo 60571063), iiProjekthi zoPhando eziSisiseko zePhondo laseHenan, eChina (Isibonelelo esinguNombolo 122300410231).
I-FY ibhale isicatshulwa sephepha kwaye i-MYH ilungiselele isampuli ye-ceramic ye-YBCO. I-FY kunye ne-MYH yenze uvavanyo kwaye yahlalutya iziphumo. I-FGC ikhokele iprojekthi kunye nokutolikwa kwenzululwazi yedatha. Bonke ababhali bawuphonononga lo mbhalo-ngqangi.
Lo msebenzi unelayisensi phantsi kwe-Creative Commons Attribution 4.0 International License. Imifanekiso okanye ezinye izinto zomntu wesithathu kweli nqaku zibandakanyiwe kwilayisenisi yenqaku leCreative Commons, ngaphandle kokuba kuboniswe ngenye indlela kumgca wetyala; ukuba imathiriyeli ayiqukwanga phantsi kwelayisensi yeCreative Commons, abasebenzisi kuya kufuneka bafumane imvume kumnini welayisenisi ukuze baphinde bavelise izinto. Ukujonga ikopi yeli phepha-mvume, ndwendwela http://creativecommons.org/licenses/by/4.0/
Yang, F., Han, M. & Chang, F. Imvelaphi yempembelelo ye-photovoltaic kwi-superconducting YBa2Cu3O6.96 ceramics. Sci Rep 5, 11504 (2015). https://doi.org/10.1038/srep11504
Ngokufaka uluvo uyavuma ukuthobela iMigaqo yethu kunye neziKhokelo zoLuntu. Ukuba ufumana into exhaphazayo okanye engahambelani nemigaqo okanye izikhokelo zethu nceda uyiphawule njengengafanelekanga.
Ixesha lokuposa: Epreli-22-2020