A-Si:H//spl mu/c-Si:H tandem solar cell by novel PECVD method

Using newly developed novel PECVD method ("Cat-PECVD method"), high quality a-Si:H films and /spl mu/c-Si:H films were successfully formed at high deposition rate of more than 1nm/s with low substrate temperature of less than 250/spl deg/C. Applying these Si films for a-Si:H//spl mu/c-Si:H tandem solar cells, initial cell efficiency of 11.5% was obtained. Owing to a low Si-H/sub 2/ bonding state content and less distorted short range order structure of the a-Si:H film, the light-induced degradation rate of tandem cell was effectively reduced to less than 7%.