The Role of Auger Recombination in InAs 1.3-/mu m Quantum-Dot Lasers Investigated Using High Hydrostatic Pressure

Abstract

InAs quantum-dot (QD) lasers were investigated in the temperature range 20-300 K and under hydrostatic pressure in the range of 0-12 kbar at room temperature. The results indicate that Auger recombination is very important in 1.3-mum QD lasers at room temperature and it is, therefore, the possible cause of the relatively low characteristic temperature observed, of T-0 = 41 K. In the 980-mn QD lasers where T-0 = 110-130 K, radiative recombination dominates. The laser emission photon energy E-las increases linearly with pressure p at 10.1 and 8.3 meV/kbar for 980 nm and 1.3-mum QD lasers, respectively. For the 980-mn QD lasers the threshold current increases with pressure at a rate proportional to the square of the photon energy E-las(2). However, la the threshold current of the 1.3-mum QD laser decreases. by 26% over a 12-kbar pressure range. This demonstrates the presence of a nonradiative recombination contribution to the threshold current, which decreases with increasing pressure. The authors show that this nonradiative contribution is Auger recombination. The results are discussed in the framework of a theoretical model based on the electronic structure and radiative recombination calculations carried out using an 8 x 8 k(.)p Hamiltonian.

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