Title :
Role of bandgap grading for the performance of a-SiGe:H based solar cells
Author :
Fölsch, J. ; Stiebig, H. ; Finger, F. ; Rech, B. ; Lundszien, D. ; Lambertz, A. ; Wagner, H.
Author_Institution :
Inst. fur Schicht- und Ionentechnik, Forschungszentrum Julich GmbH, Germany
Abstract :
The influence of bandgap grading and bandgap discontinuities on the performance of a-SiGe:H based multi-junction solar cells is investigated. Different types of bandgap grading of the i-layer, like linear profiling in asymmetrical v- and u-form, are studied with respect to their influence on the solar cell parameters under white, red and blue light illumination. Additionally, the cell series with different bandgap designs are light soaked under filtered red light for 300 h and 3000 h. Optimum performance is found for an asymmetrical v-shape with a band gap minimum close to the p/i interface. Using the concept of bandgap grading, a-Si:H/a-SiGe:H tandem and a-Si:H/a-Si: H/a-SiGe:H triple solar cells have been fabricated with efficiencies above 10%
Keywords :
Ge-Si alloys; amorphous semiconductors; energy gap; hydrogen; p-n heterojunctions; semiconductor device testing; solar cells; 300 h; 3000 h; SiGe:H; a-SiGe:H based solar cells; bandgap discontinuities; bandgap grading; light soaking; linear profiling; multi-junction solar cells; optimum performance; photovoltaic performance; Ambient intelligence; Amorphous materials; Band pass filters; Design optimization; Fingers; Lighting; Optical filters; Photonic band gap; Photovoltaic cells; Voltage;
Conference_Titel :
Photovoltaic Specialists Conference, 1996., Conference Record of the Twenty Fifth IEEE
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-3166-4
DOI :
10.1109/PVSC.1996.564331
