Giant lateral photovoltaic effect in MoS2/SiO2/Si p-i-n junction

Molybdenum disulfide (MoS2) is investigated as one typical kind of two dimensional (2D) materials for developing various kinds of electronic devices. Here, we report a giant lateral photovoltaic effect (LPE) in a MoS2/SiO2/Si p-i-n junction. MoS2 films are deposited on Si substrates using magnetron sputtering technique and a SiO2 layer is incorporated to perform the modification on the MoS2/Si interface. After the first 5-nm-thickness horizontally lying layer on the SiO2 layer, the atomic unit layers of S-Mo-S in the followed MoS2 film are almost perpendicular to the substrate surface and the vertically standing layered structure is formed. Owing to the interface modification of the SiO2 layer and the unique structure of the MoS2 film, a giant LPE is observed in the fabricated junction. The LPE shows a linear dependence on the position of the laser illumination and the considerably large sensitivity of 355.4 mV/mm is obtained with the fast response of 16.2 μs. The mechanisms to the LPE are unveiled by building the correlation between microstructures, energy-band alignment and optoelectrical properties of the MoS2/SiO2/Si junctions. The excellent LPE characteristics could make MoS2 films combined with SiO2/Si promising candidates for the application of high-performance position sensitive detectors.