Theoretical Study of Transparent Conducting Oxide and Amorphous Silicon Interface and Its Impact on the Properties of Amorphous Silicon/Crystalline Silicon Heterojunction Solar Cell

The physics of transparent conducting oxide (TCO) and n-type doped amorphous silicon interface has been studied with the aid of two-dimensional numerical simulations (Sentaurus TCAD, Synopsys), in order to determine the impact of the TCO work-function on the electrical performance of amorphous silicon (a-Si)/crystalline silicon (c-Si) heterojunction solar cell. Previous studies have indicated requirement of lower work-function for TCO in contact with n-type doped a-Si for higher solar cell efficiency. However due to the limitations in TCO deposition process conditions it is not possible to achieve a work-function below a certain value which limits the device efficiency. An alternate approach has been explored where the TCO in contact with n-type doped a-Si has been eliminated and a direct contact has been established with the metal. This has resulted in significant improvement in the calculated device efficiency due to the principal contribution from increased open circuit voltage and fill factor.