ZnTe-CdSe heterojunctions ii. photoelectric and luminescent properties

Abstract

The photoelectric properties of ZnTe-CdSe heterojunctions illuminated by natural and laser light have been investigated. The crossing of the forward branch of the I-U curves in the dark and under illumination is a characteristic peculiarity for these heterojunctions. A t 300 O K the maximum value of the open circuit voltage U,, is 0.80 V. With laser light illumination Uoc reaches 1.4 V. The region of spectral sensitivity is limited by photons with energies equal to the forbidden gap of ZnTe and CdSe. The thickness of the CdSe layer has the main influence on the shape of the spectral distribution. The reverse voltage applied to the heterojunction leads to a long-wave shift of the peak caused by the generation of electron-hole pairs in ZnTe. Two types of samples with red and green luminescence have been obtained. The external quantum efficiency a t 80 O K is equal to 1.2 to 1.6% . E~n z HccnexoBaHbr c # o~o a n e~~p z q e c~z e cBoBcTsa reTeponepexonoB p ZnTen CdSe IlpM OCBeUIeHMU O6bIYHbIM EI Jra3epHLdM CBBTOM. XapaHTepHO& oco6ea-HOCTbIO HaHHLdX ~eTepOIIepeXOAOB HBJIHeTCfI IIepeCeqeHMe IIpRMbIX BeTBefi BOJIbT-aMIlepHbIX XapaKTepHCTEIK B TeMHOTe M Ha CBeTy. npIl 300 O K MaKCUMajIbHOe ~Y~N~~H E I H OHa AOCTUraeT 1,4 B. 06JIaCTb CIIeKTpaJIbHOfi qYBCTBUTeJIbHOCTM Orpa-HUqeHa 4OTOHaMM C 3HeprUHMEI PaBHbIMU IlIHpMHe 3aIIpeWeHHOt 30HbI ZnTe M 3~a q e~~e HanpcrxceHm xonocToro xona c0cTaBncre-r 0,s B. a npu n a 3 e p~o~ ~0 3 -CdSe. Tonupma CJIOH cenemna KanMnR 0~a 3 b 1~a e~ ocHoBHoe Bnmme Ha BEIF[ cnewpanmHx xapawepacTm. IIpmoxceme 0 6 p a~~o r o cMeueHnH H reTeponepexony ~~H B O A U T K c~e w e~~m B EnmoBonHoBym CTOPOHY MaKcmyMa o6ycno-BJIeHHOrO I'eHepaqHefi 3JIeKTpOHHO-J(bIpOqHbIX nap B TeJInypEIAe UMHKB. EbIJIO IIOny.IeH0 HBa TMna 06pa3UOB C 3ene~oB II KpaCHOfi JIWMHHeCqeHqMefi. BHeIIIHUa KBaHTOBbIk BbIXOA IlpIl80 "K COCTaBJIReT 1,2 A0 l,6%.