Photoluminescence and stimulated emission in Si- and Ge-disordered AlxGa1−xAs-GaAs superlattices

Kaliski, R. W. et al. (1985) Photoluminescence and stimulated emission in Si- and Ge-disordered AlxGa1−xAs-GaAs superlattices. Journal of Applied Physics, 58(1), 101. (doi:10.1063/1.335710)

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Abstract

Photoluminescence and absorption data are presented on Al x Ga1−x As‐GaAs superlattices(SLs) disordered into bulk‐crystal Al y Ga1−y As (0≤y≤x) by Si or Gediffusion. The bulk‐crystal Al y Ga1−y As produced by impurity‐induced disordering (by Al‐Ga interchange) is determined by transmission electron microscopy, absorption measurements, and photoluminescence to be homogeneous, with an alloy composition (y) that agrees with the average Al concentration of the SL. For low enough Al concentration (y≊0.23<y c =0.44, the direct‐indirect crossover), in absorption the Ge‐ or Si‐disordered SL exhibits (4.2 and 77 K) the bulk‐crystal exciton, which is characteristic of homogeneous alloy (Al y Ga1−y As). Stimulated emission (4.2 and 77 K) in bulk‐crystal Al y Ga1−y As is observed ΔE≤50 meV below the band edge via photopumping for both Si‐ and Ge‐disordered SLs of Al concentration yielding y∼0.23 and y∼0.39. Shallow hydrogenlike donor or acceptor states are characteristic of Al x Ga1−x As‐GaAs SLs disordered with Ge or with Si. For the Si impurity (i.e., an Al x Ga1−x As‐GaAs SL disordered with Si), however, much deeper states (transitions) are observed that saturate at higher photoexcitation levels. These states are attributed to nearest‐neighbor or extended Si‐Si pairs since similarly disordered Al x Ga1−x As‐GaAs SLs doped with Ge do not exhibit deeper states.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Meehan, Professor Kathleen
Authors: Kaliski, R. W., Gavrilovic, P., Meehan, K., Gavrilovic, J., Hsieh, K. C., Jackson, G. S., Holonyak, N., Coleman, J. J., Burnham, R. D., Thornton, R. L., and Paoli, T. L.
College/School:College of Science and Engineering > School of Engineering
Journal Name:Journal of Applied Physics
Publisher:American Institute of Physics
ISSN:0021-8979
ISSN (Online):1089-7550

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