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

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 1.3m QD lasers at room temperature and it is, therefore, the possible cause of the relatively low characteristic temperature observed, of 0 = 41 K. In the 980-nm QD lasers where 0 = 110–130 K, radiative recombination dominates. The laser emission photon energy las increases linearly with pressure at 10.1 and 8.3 meV/kbar for 980 nm and 1.3m QD lasers, respectively. For the 980-nm QD lasers the threshold current increases with pressure at a rate proportional to the square of the photon energy 2 las . However, the threshold current of the 1.3m 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 8 k p Hamiltonian.