Relation between photovoltaic characteristics and acceptor concentration at the interface of indium oxide/indium phoshide heterojunction solar cell

摘要

Photovoltaic characteristics of a heterojunction solar cell composed of reactively evaporated indium oxide (In_2O_3) film and single crystalline p-type indium phosphide (InP) was found to depend on acceptor concentration at the interface. The value of acceptor concentration was preferable to be high to obtain a high performance cell because larger open-circuit voltage can be obtained due to decrease of diode saturation current of the cell with the increase of the acceptor concentration. The acceptor concentration of the cell was increased by annealing during forming an ohmic contact. The increase of acceptor concentration by annealing thought to be able to explain in terms of outdiffusion of eh interastitial zinc atoms in InP bulk. Further, the value of acceptor concentration is modified by substrate heating during deposition of transparent and conductive In_2O_3 film. In order to produce a high performance cell, low substrate temperature (200 ℃) was preferable during deposition of In_2O_3.