Investigation of Nickel Oxide as Carrier-selective Interlayer for Silicon Solar Cell Contacts

Thin film crystalline silicon (c-Si) solar cells have been a potential candidate to reduce the capital expenditure associated with traditional silicon photovoltaic market. This paper presents the sputtered NiOx to be a potential candidate as hole-selective layer for c-Si solar cell contacts. NiOx has a very small valence band offset (VBO) (~0.1 eV) and a large conduction band offset (CBO) with Si (~2 eV), which makes it a promising candidate for hole-selective interlayer materials to reduce the contact recombination. In this paper, the effect of annealing condition on the NiOx/Si interface quality is first evaluated by Hall resistivity measurement. Also, the transport of both majority and minority carriers due to NiOx/Si band alignment is investigated by transmission line measurement. Results in this paper show that the sputtered NiOx can be an effective interlayer material for thin film c-Si solar cell contacts.