In situ transmission electron microscopy studies of radiation damage in copper indium diselenide

The ternary semiconductor, CuInSe2 (CIS), is a promising semiconductor material for use in photovoltaic applications. Of particular interest is the high tolerance of this material to bombardment by energetic particles. This is of particular importance for photovoltaic applications in outer space where the lifetime of CIS-based solar cells has been found to be at least 50 times that of those based on amorphous silicon. In this paper we report on studies of the build-up of radiation damage in CIS during irradiation with Xe ions in the energy range 100–400 keV. Room temperature experiments indicate that dynamic annealing processes prevent the build-up of high levels of damage. However, for irradiation at a temperature of 50 K, the behaviour changes drastically with the material amorphising at low fluences. This effect is discussed in terms of defect mobility.