Absence of an intrinsic value for the surface recombination velocity in doped semiconductors
| Autor: | Cadiz, F., Paget, D., Berkovits, V. L., Ulin, V. P., Arscott, S., Peytavit, E., Rowe, A. C. H. |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | J. Appl. Phys. 114, 103711 (2013) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1063/1.4821139 |
| Popis: | A self-consistent expression for the surface recombination velocity $S$ and the surface Fermi level unpinning energy as a function of light excitation power ($P$) is presented for n- and p-type semiconductors doped above the 10$^{16}$ cm$^{-3}$ range. Measurements of $S$ on p-type GaAs films using a novel polarized microluminescence technique are used to illustrate two limiting cases of the model. For a naturally oxidized surface $S$ is described by a power law in $P$ whereas for a passivated surface $S^{-1}$ varies logarithmically with $P$. Furthermore, the variation in $S$ with surface state density and bulk doping level is found to be the result of Fermi level unpinning rather than a change in the intrinsic surface recombination velocity. It is concluded that $S$ depends on $P$ throughout the experimentally accessible range of excitation powers and therefore that no instrinsic value can be determined. Previously reported values of $S$ on a range of semiconducting materials are thus only valid for a specific excitation power. Comment: 10 pages, 7 figures |
| Databáze: | arXiv |
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