Study of MoS2 Deposited by ALD on c-Si, Towards the Development of MoS2/c-Si Heterojunction Photovoltaics

Silicon-based heterojunction (SHJ) solar cells demonstrate high efficiencies over their homojunction counterparts, revealing the potential of such technologies. We present here the first steps towards the development of molybdenum disulfide (MoS₂)/c-silicon heterojunction solar cells, consisting of a preliminary study of the MoS₂ material and numerical device simulations of MoS₂/Si heterojunction solar cells, using SILVACO ATLAS. Through the optical and structural characterization of MoS₂/SiO₂/Si samples, we found a significant sensitivity of the MoS₂ to ambient oxidation. Optical ellipsometry showed a bandgap of 1.87 eV for a 7 monolayer thick MoS₂ sample, suitable for the targeted application. Finally, we briefly introduce a device simulation and show that the MoS₂/Si heterojunction could lead to a gain in quantum efficiency, especially in the region with short wavelengths, compared with a standard a-Si/c-Si solar cell.