In-situ temperature and thickness control grown 2D-MoS2 via pulsed laser ablation for photovoltaic devices

Abstract

Two dimensional molybdenum disulphide thin films are fabricated via pulsed laser ablation technique and used as counter electrode for photovoltaic devices. MoS2 thin films are laser ablated using KrF excimer laser, the parameters like temperature and thickness of thin films being controlled under in-situ condition. The effects of parameters on the laser ablated MoS2 thin film exhibit a superior electrocatalytic activity thereby indicating an ability to be employed as a counter electrode in dye-sensitized solar cells. With increase in temperature, there is an improvement in crystallinity which leads to enhancement of active sites in MoS2 resulting into its effectual for use in the photo-conversion devices. Raman and XRD studies clearly confirm the formation of MoS2 and its associated phase structure. The crystalline nature and interlayer spacing of stacked MoS2 structure are observed from HRTEM. The growth and thickness of MoS2 thin films are evaluated from FESEM and AFM. Electrocatalytic behaviour of laser ablated films are carefully investigated and its photovoltaic performances are analyzed. MoS2 films fabricated under room temperature delivers photo-conversion efficiency of 1.48%, while on the increasing temperature and thickness of MoS2 films it delivers four times increase in efficiency up to 5.66% under one sun condition.