Growth and application of MoSe2 in solar cells

Abstract

MoSe2 from monolayer to bulk phase can realize the transition from a direct bandgap semiconductor to an indirect bandgap semiconductor. Its bandgap varies between 1.1 and 1.55 eV, which matches the solar spectral range, so Si-based heterojunction solar cells with MoSe2 as an active layer have great significance in the development of low-cost, high-efficiency and high-flexibility photovoltaic devices. In this work, MoSe2 thin films were synthesized by chemical vapor deposition using MoO3 and Se powders as precursor sources. The effects of different process parameters (Se source temperature, Mo source temperature, growth time, carrier gas flow rate and hydrogen ratio) on the synthesis of MoSe2 thin films were systematically investigated. The optimized experimental parameters were determined as follows: the molybdenum source temperature of 800[Formula: see text], the selenium source 20 cm away from molybdenum source, the growth time of 10 min, the carrier gas flow rate of 60 sccm, the hydrogen ratio of 10%. Then MoSe2/Si heterojunction solar cells were constructed via wet chemical transfer. The open-circuit voltage, short-circuit current density, filling factor and photovoltaic conversion efficiency of the fabricated solar cells were 0.19 V, 5.71 mA/cm2, 30.47% and 0.33%, respectively. Main factors affecting the photovoltaic performance of the MoSe2/Si solar cells have also been discussed. This work is very helpful for the development of MoSe2 material and relevant application in the field of solar cells.