Microsecond lifetimes and low interface recombination velocities in moderately doped n-GaAs thin films

• Published in: Applied physics letters Vol. 61; no. 20; pp. 2440 - 2442
• Main Authors: LUSH, G. B, MELLOCH, M. R, LUNDSTROM, M. S, LEVI, D. H, AHRENKIEL, R. K, MACMILLAN, H. F
• Format: Journal Article
• Language: English
• Published: Melville, NY American Institute of Physics 16-11-1992
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics; Semiconductor materials; Impurity; Charge carrier; Photoluminescence; Aluminium Gallium Arsenides Mixed; Experimental study; Microsecond; Time variation; Inorganic compound; Luminescence decay; Double heterojunction; Solar cell; Gallium Arsenides; Lifetime; Laser beam; Charge carrier recombination; Illumination; Selenium; Application; Interface
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.108190

We have observed lifetimes greater than 1 μs in moderately doped, thin film, n-GaAs/Al0.3Ga0.7As double heterostructure membranes formed by etching away the substrate. We attribute these ultralong lifetimes to enhanced photon recycling caused by the removal of the substrate. Nonradiative recombination in the bulk and at the interfaces is very low; the upper limit of the interface recombination velocity is 25 cm/s. Such long lifetimes in GaAs doped at ND=1.3×1017 cm−3 suggest that thin-film solar cells offer a potential option for achieving very high efficiencies.