Progress in the development of high-conversion-efficiency a-Si/μc-Si tandem solar module using μc-Si thin film with high deposition rate on Gen. 5.5 large-area glass substrate

The technology to make high-quality, high-reliability solar modules with a high deposition rate for μc-Si thin-film is a problem for the industrialization of low-cost, high-conversion-efficiency a-Si/μc-Si tandem structure solar modules. Sanyo has solved this problem by developing an original CVD technique called Localized Plasma Confinement CVD and a new evaluation method for μc-Si thin film. A stabilized conversion efficiency of 10.0% was achieved for an a-Si/μc-Si tandem structure solar module, and a deposition rate of 2.4 nm/s for μc-Si thin-film was attained on a Gen. 5.5 full-size glass substrate. To obtain a higher conversion-efficiency a-Si/μc-Si tandem structure solar module, fundamental studies of μc-Si thin-film have been performed, and a stabilized conversion efficiency of 10.5% (Initial solar module conversion efficiency: 12.0%) has been achieved on a large-area glass substrate. Furthermore, in the study of this development, the highest stabilized conversion efficiency of 12.0% (Initial conversion-efficiency: 13.5%) was attained. Module reliability tests confirmed by IEC 61646 Ed. 2 revealed that the performance of the module is adapted. These high-performance a-Si/μc-Si tandem structure solar modules were prepared by using the knowledge of our thin-film and module technologies.