Optical properties of multi-stacked InGaAs/GaNAs quantum dot solar cell fabricated on GaAs (311)B substrate

Journal Article · Sat Sep 15 00:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4752733· OSTI ID:22089461

Shoji, Yasushi ^[1]; Akimoto, Katsuhiro ^[2]; Okada, Yoshitaka ^[1]

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1. Research Center for Advanced Science and Technology (RCAST), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan)
2. Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan)

Quantum dot solar cells (QDSCs) comprised of 10 stacked pairs of strain-compensated InGaAs/GaNAs QD structure have been fabricated by atomic hydrogen-assisted molecular beam epitaxy. A homogeneous and high-density QD array structure with improved in-plane ordering and total density of {approx}10{sup 12} cm{sup -2} has been achieved on GaAs (311)B grown at 460 Degree-Sign C after stacking. The external quantum efficiency (EQE) of InGaAs/GaNAs QDSC increases in the longer wavelength range due to additive contribution from QD layers inserted in the intrinsic region. The short-circuit current density measured for QDSC is 17.2 mA/cm{sup 2} compared to 14.8 mA/cm{sup 2} of GaAs reference cell. Further, an increase in EQE due to photocurrent production by 2-step photon absorption has been observed at room temperature though it is still small at around 0.1%.

• OSTI ID: 22089461
• Journal Information: Journal of Applied Physics, Vol. 112, Issue 6; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ABSORPTION
CURRENT DENSITY
GALLIUM ARSENIDES
INDIUM COMPOUNDS
LAYERS
MOLECULAR BEAM EPITAXY
NITROGEN COMPOUNDS
OPTICAL PROPERTIES
PHOTOCONDUCTIVITY
PHOTOEMISSION
QUANTUM DOTS
QUANTUM EFFICIENCY
SEMICONDUCTOR MATERIALS
SOLAR CELLS
SUBSTRATES
TEMPERATURE RANGE 0273-0400 K