Control of intermediate-band configuration in GaAs:N δ-doped superlattice
| Autor: | Tomoya Suzuki, Yoshitaka Okada, Kazuki Osada, Hiroyuki Yaguchi, Shunya Naitoh, Yasushi Shoji, Yasuto Hijikata, Shuhei Yagi |
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| Rok vydání: | 2015 |
| Předmět: |
Materials science
Physics and Astronomy (miscellaneous) business.industry Superlattice Doping Energy conversion efficiency General Engineering General Physics and Astronomy Detailed balance Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Thermal conduction Condensed Matter::Materials Science Intermediate band Optics Physics::Accelerator Physics Optoelectronics Area density business Molecular beam epitaxy |
| Zdroj: | Japanese Journal of Applied Physics. 54:08KA04 |
| ISSN: | 1347-4065 0021-4922 |
| DOI: | 10.7567/jjap.54.08ka04 |
| Popis: | GaAs:N δ-doped superlattices (SLs) consisting of alternating layers of undoped and N δ-doped GaAs were fabricated by molecular beam epitaxy (MBE) as possible candidates for the light-absorbing material of intermediate-band solar cells (IBSCs). Since the energy gaps in IBSCs need to be adjusted to optimum values to achieve sufficiently high conversion efficiency, it is important to control precisely the band configuration of intermediate-band (IB) materials. In this study, we demonstrated the control of the IB energy configuration in GaAs:N δ-doped SLs by changing their structural parameters. Optical transitions due to the SL minibands related to the N-induced conduction subbands E+ and E− were clearly observed and the transition energies depended systematically on the N area density and period length of the SLs. Conversion efficiency calculations based on the detailed balance model indicated that IBSCs with an efficiency of nearly 60% are achievable by using the fabricated GaAs:N δ-doped SLs. |
| Databáze: | OpenAIRE |
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