Improvement on actual output power of thin film silicon HYBRID module

The I-V characteristics of thin film silicon HYBRID modules (a-Si/poly-Si stacked tandem solar-module) have been investigated under several spectral irradiance distributions. Spectral Match Analyzing Procedure (SMAP) revealed that the performance of HYBRID modules exposed under the sunlight tended to be limited by top a-Si cell due to the photo-degradation and the bottom poly-Si cell of our modules was stable. The performance of modules optimized at noon was 10% greater than at STC when the irradiance spectrum was close to AM1.0. The latest module exhibited the actual output current corresponding to the Jsc of 13 mA/cm/sup 2/ at the irradiance of 1.0 kW/m/sup 2/ in the natural sunlight, which had the efficiency of 13% and the Jsc of 13 mA/cm/sup 2/ at STC initially. The HYBRID module limited by the top cell exhibited the more efficient performance at noon. This behaviour was well understood by the trajectory analysis on the performance contour obtained by SMAP at varied module temperatures.