Ukusebenza kakuhle kweeseli zelanga kuyancitshiswa xa ii-electron-hole pairs ziphinda zihlangane ngaphambi kokuba zisetyenziswe ngokufanelekileyo. Xa i-semiconductor ifunxa ukukhanya kwi-wavelength efanelekileyo, ii-electron-hole pairs zenziwa. Phantsi kokukhanya, uxinzelelo lwe-carrier kwisixhobo ludlula ixabiso laso lokulingana. Nje ukuba umthombo wokukhanya ususwe, uxinzelelo lwe-carrier luyabola lubuyele kwimeko yalo yokulingana kwinkqubo ebizwa ngokuba yi-recombination. Ngezantsi kukho iindlela ezahlukeneyo zokudibanisa:
1. Ukuphinda Ufumane Imitha
Ukuphinda kufakwe imisebe yindlela echaseneyo nenkqubo yokufunxwa kokukhanya, apho i-electron itshintsha ukusuka kwimeko yamandla aphezulu ukuya kwimeko yamandla aphantsi, ikhupha amandla agqithisileyo njengokukhanya. Olu hlobo lokuphinda kufakwe lubalulekile kwiilaser ze-semiconductor kunye nee-diode ezikhupha ukukhanya (ii-LED) kodwa alukho kwi-silicon solar cells.
2. Ukudibanisa iAuger
Ukuphinda-phinda i-Auger yinkqubo echaseneyo ye-impact ionization. Xa i-electron kunye nomngxuma ziphinda zihlangane, amandla agqithisileyo adluliselwa kwenye i-electron endaweni yokuba akhutshwe njengokukhanya. I-electron evuselelwe emva koko ibuyela kwimeko yayo yokuqala, ikhupha ii-phonon (amandla okudlidliza). Ukuphinda-phinda i-Auger kuvakala ngakumbi kwizinto ezixutywe kakhulu, ngakumbi xa uxinzelelo lokungcola ludlula i-10¹⁷ cm⁻³, nto leyo eyenza ukuba ibe yinkqubo ebalaseleyo yokuphinda-phinda kwiimeko ezinjalo.
3. Ukuphinda Uhlangane Ngokuncediswa Yitraphu
Ukungcola kunye neziphene kwii-semiconductors kudala amanqanaba amandla avumelekileyo ngaphakathi kwe-bandgap engavumelekanga. La manqanaba amandla esiphene aququzelela inkqubo yokuphinda-phinda kwamanyathelo amabini: i-electron iqala iphumle ukusuka kwi-conduction band ukuya kwinqanaba lesiphene ize emva koko iye kwi-valence band, apho iphinda ihlangane nomngxuma. Le nkqubo isebenza kakhulu ekukhuthazeni ukuphinda-phinda kwaye inokuchaphazela kakhulu ukusebenza kweeseli zelanga.
4. Ukuphinda Uhlangane Komphezulu
Umphezulu we-semiconductor ungabonwa njengendawo eneziphene ezininzi ngenxa yokuphela kwesakhiwo sekristale. Ezi ziphene zomphezulu zidala iimeko ezininzi zamandla ngaphakathi kwe-bandgap engavumelekanga, apho ukuphinda-phinda kunokwenzeka ngokulula. Ukuphinda-phinda komphezulu yinto ebalulekileyo kuba isakhiwo sekristale kumphezulu asiqhelekanga kakhulu, nto leyo eyenza ukuba ukuphinda-phinda kwenzeke kwezi ndawo.
Isiphelo
Kwiiseli zelanga ezisebenzayo, ezi ndlela zokuphinda zisebenze zinegalelo ekulahlekelweni kokusebenza ngokubanzi. Umsebenzi wabayili beeseli kukunciphisa ezi lahleko ukuphucula ukusebenza kakuhle. Inkqubo nganye yokuphinda isebenzise inika imingeni eyahlukeneyo, kwaye ukoyisa ezi ngokukhetha izinto, ukuhambisa umphezulu, kunye namanqanaba okuphucula i-doping kubalulekile ekuphuculeni ukusebenza kweeseli zelanga. Ukongeza, iimpawu zoyilo ezahlukeneyo zahlula iiseli zelanga ezahlukeneyo zorhwebo kwimarike, zichaphazela ukusebenza kwazo kunye nokukwazi kwazo ukusetyenziswa.
