High voltage ZnSe/CuInSe2 solar cells

This paper describes investigations of CIS solar cells based on ZnSe window layers deposited by MOCVD. Investigations of ZnSe/CIS solar cells are being carried out to determine if ZnSe is a viable alternative to CdS as a window material. MOCVD growth of ZnSe is accomplished in a SPIRE 500XT reactor and conductive n‐type ZnSe is grown by using iodine as a dopant. ZnSe films have been grown on CIS substrates at 200 °C to 250 °C. ZnO is also being deposited by MOCVD by reacting tetrahydrofuran (THF) with a zinc adduct. ZnSe/CIS heterojunctions have been studied by growing n‐ZnSe films onto 2 cm × 2 cm CIS substrates diced from materials supplied by Siemens. Test cells are fabricated by depositing thin, transparent Al contacts 2.8 mm in diameter on top of the ZnSe to serve as contacts. These test devices typically exhibit open circuit voltages ≳500 mV and estimated active area efficiencies ≳13%. Efforts to deposit ZnO onto ZnSe/CIS structures for top contact layers have usually resulted in photocurrent suppre...