Title :
High efficiency large area multi-junction solar cells incorporating a-SiGe∶H and nc-Si∶H using MVHF technology
Author :
Xu, X. ; Su, T. ; Beglau, D. ; Ehlert, S. ; Pietka, G. ; Bobela, D. ; Li, Y. ; Lord, K. ; Yue, G. ; Zhang, J. ; Yan, B. ; Worrel, C. ; Beernink, Kevin ; DeMaggio, G. ; Banerjee, A. ; Yang, J. ; Guha, S.
Author_Institution :
United Solar Ovonic LLC, Troy, MI, USA
Abstract :
We fabricated five different types of a-SiGe:H and nc-Si:H based multi-junction solar cell structures using modified very high frequency (MVHF) technology. After optimization, all five structures reached similar initial cell performance, i.e. ~12% small active-area (0.25 cm2) efficiency and 10.6-10.8% large aperture-area (¿ 400 cm2) efficiency after encapsulation. However, they showed quite different light soaking stability behavior, which can be attributed to the degradation of component cells. We conducted a comparative study between the MVHF deposited solar cells with those deposited by RF. Materials studies were also conducted to understand the mechanism responsible for better stability for the MVHF deposited a-SiGe:H solar cells. The best stable efficiency achieved for the large-area encapsulated cells is approaching 10% for both a-SiGe:H and nc-Si:H based multi-junction cells.
Keywords :
Ge-Si alloys; elemental semiconductors; hydrogen; optimisation; silicon; solar cells; Si:H; SiGe:H; SiGe:H solar cells; cell performance; high efficiency large area multijunction solar cells; modified very high frequency technology; optimization; soaking stability; Indium tin oxide; Laboratories; Manufacturing; Photovoltaic cells; Plasma properties; Radio frequency; Renewable energy resources; Stability; Substrates; Zinc oxide;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2009 34th IEEE
Conference_Location :
Philadelphia, PA
Print_ISBN :
978-1-4244-2949-3
Electronic_ISBN :
0160-8371
DOI :
10.1109/PVSC.2009.5411410
