Design and fabrication of graphene/CdS Schottky junction for photovoltaic solar cell applications

In this report, we study the optimal design and simulation of Schottky junction solar cells consisting of cadmium sulfide (CdS) and graphene layer using Silvaco TCAD Atlas software. During device modeling the thickness of the top layer of graphene as an electrode and the middle semiconducting layer of CdS as an active region is taken as 10 and 70 nm, respectively. Polyethylene terephthalate (PET) is used as the flexible substrate for the study. We also report the fabrication of flexible solar cells on PET substrates composed of CdS and graphene synthesized in-house by solution process. The I-V characteristics have been undertaken in both the simulated and fabricated devices with structure graphene/CdS/PET. Under AM 1.5 G, the fabricated device with the structure graphene/CdS/PET shows an open- circuit voltage (Voc) of 0.163 V, a short circuit current density (Jsc) of 0.00063 A/m2 and a fill factor (FF) of 56.50%. The Ideality factor and reverse saturation current of the device is determined to be 9.6 and 0.063 µA, respectively.