Homojunction GaAs solar cells grown by close space vapor transport
- University of Oregon
- Lawrence Berkeley National Laboratory
We report on the first pn junction solar cells grown by homoepitaxy of GaAs using close space vapor transport (CSVT). Cells were grown both on commercial wafer substrates and on a CSVT absorber film, and had efficiencies reaching 8.1%, open circuit voltages reaching 909 mV, and internal quantum efficiency of 90%. The performance of these cells is partly limited by the electron diffusion lengths in the wafer substrates, as evidenced by the improved peak internal quantum efficiency in devices fabricated on a CSVT absorber film. Unoptimized highly-doped n-type emitters also limit the photocurrent, indicating that thinner emitters with reduced doping, and ultimately wider band gap window or surface passivation layers, are required to increase the efficiency.
- Research Organization:
- Department of Physics, Department of Chemistry and Biochemistry, and the Materials Science Institute at University of Oregon; The Molecular Foundry, Lawrence Berkeley National Laboratory
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
- DOE Contract Number:
- EE0005957
- OSTI ID:
- 1222730
- Report Number(s):
- DOE-UO-05957-2
- Resource Relation:
- Conference: Photovoltaic Specialist Conference (PVSC), 2014 IEEE 40th
- Country of Publication:
- United States
- Language:
- English
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