Characterization of sputtered nanocrystalline gallium nitride for electron selective contact of crystalline silicon solar cell

We investigated properties of sputtered nanocrystalline gallium nitride (nc-GaN) to discuss the potential of the nc-GaN as an electron selective contact in a silicon heterojunction (SHJ) solar cell. Modeling of nc-GaN/crystalline silicon (c-Si) heterojunction was carried out based on the analysis of the deposited nc-GaN films and nc-GaN/c-Si heterojunction devices. The simulation using the developed model well reproduced the current-voltage characteristics of a SHJ solar cell with nc-GaN layer. The device simulation pointed out that it is important to use nc-GaN with electron concentration larger than 5 × 1018 cm−3 and metal contact with work function less than 3.9 eV to obtain good solar cell performance.