Understanding the influence of recombination dynamics on hot carrier populations in III-V nanowires

Hot carrier solar cells represent a category of 3<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> photovoltaic devices aimed at improving the efficiency of solar technology beyond the theoretical limits of single-junction cells. A key factor in designing effective hot carrier solar cells is minimizing the thermalization rates of hot carriers within the solar cell absorbers. Nanowires (NWs) offer promising potential for hot carrier solar cells due to their one-dimensional structure and favorable density-of-states characteristics. This study investigates the influence of recombination dynamics— Shockley-Read-Hall (SRH), radiative, and Auger recombination—on the properties of photogenerated hot carriers in nanostructures. The nanowires examined consist of III-V semiconductors, which can exhibit distinct effects of these recombination processes on their optical emission. Findings from photoluminescence spectroscopy reveal a significant correlation between hot carrier effects and the diameter of core-shell InGaAs nanowires due to their microstructural properties. The results indicate that the influence of hot carriers increases as the contribution of Auger recombination (or Auger heating) becomes more pronounced in these nanostructures. Furthermore, the study of hot carrier properties in core-shell GaAsSb NWs that are free from planar defects indicates that the InGaAs NWs exhibit more substantial hot carrier effects due to enhanced Auger heating. Understanding the significance of Auger recombination on hot carrier properties can open new avenues for designing efficient hot carrier absorbers for photovoltaic solar cell applications.