Tunable work function of a WO_X buffer layer for enhanced photocarrier collection of pin-type amorphous silicon solar cells

摘要

An in situ postdeposition ultraviolet treatment was proposed to improve the electrical properties of a tungsten oxide (WO_X) buffer layer of pin-type amorphous silicon-based solar cell. Based on the x-ray and ultraviolet photoelectron spectroscopy and the activation energy measurements, it was found that the work function of WO_X is tunable by ultraviolet light treatment, and the collection performance of solar cells incorporating WO_X with the lower work function is further improved. Moreover, the optimal band alignment scheme for a window layer is discussed in terms of obtaining enhanced carrier collection without open circuit voltage degradation.