Investigations on Integration of CdS/CdTe Thin Film Solar Cell with Supercapacitor

Photo-supercapacitors (PSCs) are independent energy sources serving the cause of simultaneous photoelectric conversion and energy storage. Insights on the working of PSCs are inevitable to realize higher efficiencies in these integrated systems and so theoretical analyses are highly required. A theoretical study on PSC comprising a CdS/CdTe thin film solar cell with a supercapacitor is carried out. The device physics of the solar cell is characterized by Sah-Noyce-Shockley (SNS) theory and the Electrical Circuit Model is used to model the working of supercapacitor. The temporal evolution of the PSC charging is theoretically simulated by the differential equation of the integrated circuit, solved using numerical methods. The effect of solar cell factors on the PSC charging is studied. With the optimized solar cell parameters, the maximum value of Energy Conversion and Storage Efficiency (ECSE_max %) of about 8.8% can be achieved with the proposed PSC.