Comprehensive Research on Stability of Amorphous Silicon and Alloy Materials and Devices

Dalal, V. K. ; Han, K. ; Maxson, T. ; Girvan, R. ; Kaushal, S. ; DeBoer, S. ; Ping, E. ; Haroon, S.

National Renewable Energy Laboratory (U.S.)

关键词: 14 Solar Energy;    Energy Beam Deposition;    Single-Junction Solar Cells;    Electron Cyclotron-Resonance;    36 Materials Science;   

DOI  :  10.2172/765093
RP-ID  :  NREL/SR-520-28989
RP-ID  :  AC36-99GO10337
RP-ID  :  765093

美国|英语

来源: UNT Digital Library

【 摘 要 】

In this report, the authors describe the work done to improve the material and device properties of a-Si:H and a-(Si,Ge):H alloys prepared using electron cyclotron resonance (ECR) plasma deposition and to understand the growth chemistry. Major results were obtained in the following areas: (1) Influence of plasma chemistry on properties and stability of a-Si:H single-junction solar cells; (2) Fabrication of good-quality tandem-junction cells. The authors made tandem-junction a-Si/a-Si cells with excellent voltages and fill factors using the H-ECR process; (3) Growth of high-quality a-(Si,Ge):H films using the ECR deposition process; (4) Fabrication of single-junction devices in a-(Si,Ge):H for diagnosing the material; and (5) Graded-gap cells in a-(Si,Ge):H. Good devices were produced using a graded-gap I-layer. In summary, the most important finding from this research has been that plasma chemistry plays a very important role in determining the properties of the materials, particularly the properties of the a-(Si,Ge):H alloy system. Even in a-Si:H, plasma chemistry plays a role in determining stability. This result suggests that by deliberately changing the chemistry of deposition, one may be able to further improve the a-(Si,Ge):H materials system and make its properties comparable to the properties of a-Si:H. The ECR reactor has proved to be a very useful chemical tool, with excellent control over growth chemistry.