The microstructure of thin film CdSe following cadmium chloride activation treatment

Thin film CdSe is an important precursor layer for CdSeTe/CdTe photovoltaic devices and as a potential future top cell in multijunction devices. It is also used in photodetectors. In this paper we report on the improvements in the microstructure of CdSe thin films caused by the cadmium chloride (CdC12) treatment. Using high resolution cross-sectional HRTEM and EBSD, we show that the CdCl2 treatment leads to recrystallisation, grain growth, texture randomization and defect removal. These improvements in microstructure result in a dramatic increase in luminescence and carrier lifetime as measured using PL and TRPL.