Interfacial engineering of Cu(In, Ga)Se{sub}2 thin film solar cells based on atomic layer epitaxy

摘要

Interface engineering of high efficiency CIS solar cells by Atomic Layer Epitaxy (ALE) has been studied. ALE deposition of ZnO layers and selected buffer layers based on zinc oxysulfide and indium sulfide has been investigated. In situ analysis of the growth is made by quartz crystal microgravimetry. New insights are given concerning extrinsic doping mechanisms with Al. Cells made with Indium sulfide buffer layers proved a superior quality, with an efficiency of 13.5%. A mixed approach is also presented where surface control of CIGS is performed from solutions prior to ALE deposition of ZnO. Best efficiencies are also obtained with indium based treatments (12.7%), but with a selenium environment.