Capacitance-Voltage Characterization of Solar Cells with CdS in CdTe Matrix
- PDF / 243,508 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 26 Downloads / 168 Views
1260-T13-04
Capacitance-Voltage Characterization of Solar Cells with CdS in CdTe Matrix Rashmi Jha1, Xiangxin Liu2, K.A. Wieland2, Jorhan Ordosgoitti1, Naba Paudel2, Kai Sun3, and Alvin Compaan2 1 Department of Electrical Engineering and Computer Science University of Toledo, Toledo, Ohio 43606, U.S.A. 2 Department of Physics and Astronomy University of Toledo, Toledo, Ohio 43606, U.S.A. 3 Electron Microbeam Analysis Laboratory (North Campus), University of Michigan, Ann Arbor, MI 48109-2143
ABSTRACT Solar cells fabricated from a sputtering target with 5% cadmium sulfide (CdS) intermixed cadmium telluride (CdTe) material was studied using Capacitance-Voltage (CV) profiling. The average efficiency of a set of these novel solar cells under one sun illumination was observed to be 7.56%. In contrast with standard sputtered CdS/CdTe cells, the junction capacitance of the mixed compound device was observed to show minimal change in the entire reverse bias range. The element mapping of the film using Bright Field Scanning Transmission Electron Microscopy (BF-STEM) was used to determine the distribution of S, Te, Cd, O, and Cl in CdTe film. From these observations, it is believed that the morphology and composition of the film resulted in a built-in potential which was sufficient to completely deplete the film. INTRODUCTION In order to meet the future energy demands and reduce our dependency on non-renewable energy sources, CdS/CdTe based thin film photovoltaic (PV) devices have been widely studied for high-efficiency and low-cost harvesting of solar energy. In the current state of research, most of these devices are based on stacks of CdS and CdTe thin films to create an n-p junction. While a high efficiency of 14% has been demonstrated in these devices using sputtter deposition, there is a significant research interest in further improving the efficiency by minimizing the thickness of CdS film [1,2]. By minimizing the thickness of CdS film, more light will enter the CdTe to generate charge carriers. However, deposition of an ultra-thin layer (
Data Loading...
