GaAs/AlGaAs quantum wells with indirect-gap AlGaAs barriers for solar cell applications
- National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan)
We have fabricated GaAs/AlGaAs quantum well (QW) solar cells in which 3 nm-thick QWs and indirect-gap Al{sub 0.78}Ga{sub 0.22}As barriers are embedded, and we studied extraction processes of photogenerated carriers in this QW system. The photocurrent under 700 nm light illumination at voltages close to the open-circuit voltage shows only a small reduction, indicating that the carrier recombination inside QWs is largely suppressed. We attribute this result to an efficient extraction of electrons from the QWs through the X-valley of AlGaAs. The insertion of QWs is shown to be effective in extending the absorption wavelengths and in enhancing the photocurrent. The use of indirect-gap materials as barriers is found to enhance carrier extraction processes, and result in an improved performance of QW solar cells.
- OSTI ID:
- 22258598
- Journal Information:
- Applied Physics Letters, Vol. 104, Issue 12; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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