Auger recombination in InN thin films

Abstract

Auger recombination is studied in InN thin films using an ultrafast time-resolved photoluminescence apparatus. The decay rates are analyzed with nonlinear dependence of the photoluminescence intensity on the carrier concentration. The fitted radiative recombination coefficients at a temperature of 35K are consistent with the theoretical prediction. The Auger rates are small at low carrier concentrations but increase quadratically with the carrier concentration. The Auger activation energies of 4.3 and 9.0meV obtained from the temperature-dependent Auger coefficient indicate that Auger recombination is weakly dependent on temperature and is a phonon-assisted process.

Nonlinear carrier recombination and transport features in highly excited InN layer

“…measurements (at 1.58 eV) [4] and ultrafast time-resolved photoluminescence (TRPL at 1.53 eV pump) [5] revealed the Auger recombination process with the linear [4] or quadratic [5] ) at interband photoexcitation (hν = 1.17 eV). Monitoring of the spatial and temporal carrier dynamics via light diffraction provided a direct way to control the dynamics of photoexcited carrier density N (i.e.…”

“…As the all recombination mechanisms were found of comparable decay rate (5 to 30 ns -1 for Auger and 10-20 ns -1 for SHR), the discrimination of their contributions as well as the determination of radiative and Auger coefficients seems not very reliable from ultrafast PL kinetics. Moreover, the authors of [4,5] did not account for carrier diffusion which can significantly contribute to carrier in-depth redistribution after short pulse photoexcitation by moving the nonequilibrium carriers out of the detection region of PL or DR techniques, thus leading to strongly non-exponential relaxation kinetics [7]. The latter peculiarity explained the origin of the fast PL signal decay component in nonhomogeneously excited high-quality HVPE, hetero-and homoepotaxial layers of GaN [7,8].…”

“…The modelling provided a value of trap-assisted Auger recombination coefficient B * = C TAA N T = 8×10 [6]. As for the PL study [5], the Auger contribution was found only in the early stage of PL decay (i.e. during the first 100 ps after photoexcitation) and in strong competition with the simultaneous role of defect-governed (Shokley-Read-Hall, SRH) and radiative recombination.…”

Temperature-dependent efficiency droop in InGaN-based light-emitting diodes induced by current crowding

“…The phonon-assisted process has weaker temperature dependence compared to the band-to-band process [16]; therefore, the activation energy E C in nitrides would be smaller than typical values obtained for the band-to-band process. Although the Auger activation energy in InGaN materials is still debatable, we employ E C = 4.3 meV based on the results presented in [17]. Reported room-temperature SRH coefficient values in InGaN are between 4.0 × 10 6 s −1 [18] and 2.0 × 10 8 s −1 [19].…”

“…Reported room-temperature SRH coefficient values in InGaN are between 4.0 × 10 6 s −1 [18] and 2.0 × 10 8 s −1 [19]. In this paper SRH recombination was modelled assuming A = 3.0 × 10 7 s −1 at 300 K and using linear temperature decrease down to 2.0 × 10 7 s −1 at 150 K according to the experimental data [17] and theoretical calculations [20].…”