We report the use of a simple close-spaced vapor transport technique for the growth of high-quality epitaxial GaAs films using potentially inexpensive GaAs powders as precursors. The free carrier type and density (1016 to 1019 cm−3) of the films were adjusted by addition of Te or Zn powder to the GaAs source powder. We show using photoelectrochemical and electron beam-induced current analyses that the minority carrier diffusion lengths of the n- and p-GaAs films reached ∼3 μm and ∼8 μm, respectively.
Hall mobilities approach those achieved for GaAs grown by metal–organic chemical vapor deposition, 1000–4200 cm2 V−1 s−1 for n-GaAs and 50–240 cm V−1 s−1 for p-GaAs depending on doping level. We conclude that the electronic quality of GaAs grown by close-spaced vapor transport is similar to that of GaAs made using conventional techniques and is thus sufficient for high-performance photovoltaic applications.
Ritenour, A.J., Boucher, J.W., DeLancey, R., Greenaway, A.L., Aloni, S. and Boettcher, S.W., 2015. Doping and electronic properties of GaAs grown by close-spaced vapor transport from powder sources for scalable III–V photovoltaics. Energy & Environmental Science, 8(1), pp.278-285.
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Categories: Solar & Photovoltaics