n-MoS 2 /p-Si Solar Cells with Al 2 O 3 Passivation for Enhanced Photogeneration.

Molybdenum disulfide (MoS2 ) has recently emerged as a promising candidate for fabricating ultrathin-film photovoltaic devices. These devices exhibit excellent photovoltaic performance, superior flexibility, and low production cost. Layered MoS2 deposited on p-Si establishes a built-in electric field at MoS2 /Si interface that helps in photogenerated carrier separation for photovoltaic operation. We propose an Al2 O3 -based passivation at the MoS2 surface to improve the photovoltaic performance of bulklike MoS2 /Si solar cells. Interestingly, it was observed that Al2 O3 passivation enhances the built-in field by reduction of interface trap density at surface. Our device exhibits an improved power conversion efficiency (PCE) of 5.6%, which to our knowledge is the highest efficiency among all bulklike MoS2 -based photovoltaic cells. The demonstrated results hold the promise for integration of bulklike MoS2 films with Si-based electronics to develop highly efficient photovoltaic cells.