RADIATIVE RECOMBINATION IN N-TYPE AND P-TYPE GAAS COMPENSATED WITH LI
1993 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 74, 7275-7287 p.Article in journal (Refereed) Published
We report fundamental changes of the radiative recombination in a wide range of n-type and p-type GaAs after diffusion with the group-I element Li. These optical properties are found to be a bulk property and closely related to the electrical conductivity of the samples. In the Li-doped samples the radiative recombination is characterized by emissions with excitation-dependent peak positions which shift to lower energies with increasing degree of compensation and concentration of Li. These properties are shown to be in qualitative agreement with fluctuations of the electrostatic potential in strongly compensated systems. For Li-diffusion temperatures above 700-800-degrees-C semi-insulating conditions with electrical resistivity exceeding 10(7) OMEGA cm are obtained for all conducting starting materials. In this heavy Li-doping regime, the simple model of fluctuating potentials is shown to be inadequate for explaining the. experimental observations unless the number of charged impurities is reduced through complexing with Li. For samples doped with low concentrations of Li, on the other hand, the photoluminescence properties are found to be characteristic of impurity-related emissions.
Place, publisher, year, edition, pages
1993. Vol. 74, 7275-7287 p.
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:kth:diva-60831DOI: 10.1063/1.354993OAI: oai:DiVA.org:kth-60831DiVA: diva2:481489
NR 201408052012-01-212012-01-152012-01-21Bibliographically approved