Hot carrier dynamics in III-V semiconductor nanowires under dominant radiative and Auger recombination

One-dimensional structures such as nanowires (NWs) show great promise in tailoring the rates of hot carrier thermalization in semiconductors with important implications for the design of efficient hot carrier absorbers. However, the fabrication of defect-free crystal structures and control of their intrinsic electronic properties can be challenging, raising concerns about the role of competing radiative and non-radiative recombination mechanisms that govern hot carrier effects. Here, we elucidate the impact of crystal purity and altered electronic properties on the hot carrier properties by comparing two classes of III-V semiconductor NW arrays with similar bandgap energies and geometries, yet different crystal quality: one composed of GaAsSb NWs, which host antisite point defects but are free of planar stacking defects, and the other InGaAs NWs with a very high density of stacking defects. Photoluminescence spectroscopy demonstrates distinct hot carrier effects in both NW arrays; however, the InGaAs NWs exhibit stronger hot carrier effects, as evidenced by increased carrier temperature under identical photo-absorptivity. This difference arises from higher rates of Auger recombination in the InGaAs NWs due to their increased n-type conductivity, as confirmed by excitation power-dependent measurements. Our findings suggest that while enhancing material properties is crucial for improving the performance of hot carrier absorbers, optimizing conditions to increase the rates of Auger recombination will further boost the efficiency of these devices.