Decay of stimulated and spontaneous emission in highly excited homoepitaxial GaN
The high-density effects in the recombination of electron{endash}hole plasma in photoexcited homoepitaxial GaN epilayers were studied by means of transient photoluminescence at room temperature. Owing to the {open_quotes}backward{close_quotes} and {open_quotes}lateral{close_quotes} photoluminescence measurement geometries employed, the influence of stimulated transitions on the decay of degenerate nonthermalized plasma was revealed. The lateral stimulated emission was demonstrated to cause a remarkable increase in the recombination rate on the early stage of the luminescence transient. A delayed enhancement of the stimulated emission due to the cooling of plasma from the initial temperature of 1100 K was observed. After completion of the thermalization process and exhaustion of the stimulated emission, the spontaneous-luminescence decay exhibited an exponential slope that relates to the nonradiative recombination of the carriers. The homoepitaxially grown GaN layer featured a luminescence decay time of 445 ps that implies a room-temperature free-carrier lifetime of 890 ps (considered to be extremely high for undoped hexagonal GaN). {copyright} 2001 American Institute of Physics.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40204279
- Journal Information:
- Applied Physics Letters, Vol. 78, Issue 24; Other Information: DOI: 10.1063/1.1378802; Othernumber: APPLAB000078000024003776000001; 014124APL; PBD: 11 Jun 2001; ISSN 0003-6951
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
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