Optimization towards high density quantum dots for intermediate band solar cells grown by molecular beam epitaxy

Journal Article · Mon Feb 08 00:00:00 EST 2010 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3313938· OSTI ID:21347268

Zhou, D; Sharma, G; Fimland, B O ^[1]; Thomassen, S F; Reenaas, T W ^[2]

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1. Department of Electronics and Telecommunications, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway)
2. Department of Physics, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway)

We report high density quantum dots (QDs) formation with optimized growth temperature and V/III ratio. At lower growth temperature, QD density is increased, due to smaller surface migration length of In adatoms. With higher V/III, the QD density is higher but it results in large clusters formation and decreases the QD uniformity. The QD solar cell was fabricated and examined. An extended spectral response in contrast to the GaAs reference cell was presented but the external quantum efficiency at energies higher than GaAs band gap is reduced, resulting from the degradation for the emitter above the strained QD layers.

• OSTI ID: 21347268
• Journal Information: Applied Physics Letters, Vol. 96, Issue 6; Other Information: DOI: 10.1063/1.3313938; (c) 2010 American Institute of Physics; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
CRYSTAL GROWTH
ENERGY GAP
GALLIUM ARSENIDES
LAYERS
MIGRATION LENGTH
MOLECULAR BEAM EPITAXY
OPTIMIZATION
QUANTUM DOTS
QUANTUM EFFICIENCY
RESIDUAL STRESSES
SEMICONDUCTOR MATERIALS
SOLAR CELLS
SPECTRAL RESPONSE
ARSENIC COMPOUNDS
ARSENIDES
CRYSTAL GROWTH METHODS
DIMENSIONS
DIRECT ENERGY CONVERTERS
EFFICIENCY
EPITAXY
EQUIPMENT
GALLIUM COMPOUNDS
LENGTH
MATERIALS
NANOSTRUCTURES
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PNICTIDES
SOLAR EQUIPMENT
STRESSES