Optical study of p-doping in GaAs nanowires for low-threshold and high-yield lasing

Semiconductor nanowires suffer from significant non-radiative surface recombination, however, heavy p-type doping has proven to be a viable option to increase the radiative recombination rate and hence quantum efficiency of emission, allowing demonstration of room-temperature lasing. Using a large-scale optical technique, we have studied Zn-doped GaAs nanowires to understand and quantify the effect of doping on growth and lasing properties. We measure the non-radiative recombination rate (knr) to be (0.14 ± 0.04) ps−1 by modelling the internal quantum efficiency (IQE) as a function of doping level. By applying a correlative method, we identify doping and nanowire length as key controllable parameters determining lasing behavior, with reliable room-temperature lasing occurring for p &3 × 1018 cm−3 and lengths & 4 µm. We report a best-in-class core-only near-infrared nanowire lasing threshold of ∼ 10 µJ cm−2 , and using a data-led filtering step, we present a method to simply identify sub-sets of nanowires with over 90% lasing yield.