Experimental investigation of a field effect back surface passivation of silicon solar cells

An independent MOS structure is added to an operating silicon solar cell in order to gain insight into the effects of an electric field on the surface passivation of silicon solar cells. This solar cell structure allows the modulation of effective back surface recombination velocity (BSRV) and hence solar cell performance. All three bias regions of a MOS system (accumulation, depletion and inversion) are examined. The combined effects of carrier injection levels, oxide charges and gate bias voltage on the device operation and BSRV are experimentally investigated. The biasing conditions of the MOS system are found to be important to the solar cell performance. The methods of locating the optimum biasing condition of the MOS system are described