The rate of radiative recombination in the nitride semiconductors and alloys

Abstract

The radiative recombination rates of free carriers and lifetimes of free excitons have been calculated in the wide band gap semiconductors GaN, InN, and AlN of the hexagonal wurtzite structure, and in their solid solutions Ga x Al 1Ϫx N, In x Al 1Ϫx N and Ga x In 1Ϫx N on the base of existing data on the energy band structure and optical absorption in these materials. We determined the interband matrix elements for the direct optical transitions between the conduction and valence bands, using the experimental photon energy dependence of absorption coefficient near the band edge. In our calculations we assumed that the material parameters of the solid solutions ͑the interband matrix element, carrier effective masses, and so on͒ could be obtained by a linear interpolation between their values in the alloy components. The temperature dependence of the energy gap was taken in the form proposed by Varshni ͓Physica 34, 149 ͑1967͔͒. The calculations of the radiative recombination rates were performed in a wide range of temperature and alloy compositions.

Electronic Properties of InGaN/GaN Vertical‐Cavity Lasers

“…using the bimolecular recombination coefficient B = 5 × 10 −11 cm 3 s −1 [13] (n i -intrinsic density). The defect-related SRH recombination rate is given by…”

Physics of high-power InGaN/GaN lasers

“…The ShockleyRead-Hall (SRH) recombination lifetime of electrons and holes is assumed to be 1 ns; however, this is a rough estimate since the type and density of recombination centres are sensitive to the technological process. Within passive layers, a spontaneous emission parameter of B ¼ 2 Â 10 À11 cm 3 s À1 is employed [8]. The spontaneous recombination rate in quantum wells is larger than in passive layers and it is calculated by integration of the spontaneous emission spectrum.…”

Localization of carriers and polarization effects in quaternary AlInGaN multiple quantum wells

“…We took into account the screening of electric field by photoexcited carriers 21 whose number was estimated from the laser excitation power density after assuming that square recombination of carriers predominates. 22 The results of these theoretical estimations are shown in Fig. 2 as the solid curve.…”

“…22 In 0.02 Ga 0.76 N/Al 0.38 In 0.01 Ga 0.61 N multiple quantum wells ͑MQWs͒, which were grown over sapphire substrates by a pulsed atomic-layer epitaxy technique. By comparing the excitation-power density and temperature dependence of the PL spectra of MQWs and bulk quaternary AlInGaN layers, we show this emission band to arise from the carrier and/or exciton localization at the quantum well interface disorders.…”

“…22 In 0.02 Ga 0.76 N multiple quantum wells ͑MQWs͒ and bulk epilayers grown by a pulsed atomiclayer epitaxy technique. A low-energy PL emission band is observed.…”