Vanadium Oxide Hole-Selective Contact for Crystalline Silicon Solar Cells

The selection of an appropriate thin-film deposition process is crucial for enhancing the efficiency of crystalline silicon (c-Si) solar cells. In this work, we investigate the development of hole-selective contacts for c-Si solar cells utilizing vanadium oxide (V 2 O x ) thin films, deposited via atomic layer deposition (ALD) and thermal evaporation techniques. We systematically compare the passivation and contact performance of V 2 O x films on p -type c-Si substrates, focusing on the influence of different oxygen sources, water and ozone, used in the ALD process. Our experimental results reveal that V 2 O x films deposited using ALD with water as the oxygen source exhibit superior passivation and contact properties due to enhanced hydrogen passivation at the c-Si/V 2 O x interface. Furthermore, the introduction of a thin aluminum oxide interfacial layer at the c-Si/V 2 O x interface further improves passivation, enabling power conversion efficiencies exceeding 22%. These findings underscore the potential of ALD-deposited V 2 O x films, particularly with water as the oxygen source, as promising candidates for optimizing hole-selective contacts in high-efficiency c-Si solar cells.