Influence of Hot-Carrier Extraction from a Photovoltaic Absorber: An Evaporative Approach

The effect of energy-selective extraction on a hot carrier's population is addressed in this study. Using an evaporative cooling model inspired by the field of cold atoms, we derive an analytical expression supported by numerical calculations to account for the removal of particles from the distribution and subsequent energy redistribution among the remaining carriers. Depending on the filtering dimensionality and energy level of extraction, the distribution can be either heated up or cooled down, resulting in a modification of the current-voltage characteristic associated to the structure. The negative differential resistance peak indicating the selective extraction is shown to be markedly reduced when evaporation is considered, which may lead to an overestimation of the tunneling current in previous models. These results provide insights into the interpretation of experimental results on energy-selective contacts, as well as a straightforward method to unequivocally demonstrate the energy filtering of hot carriers in a structure operating under continuous illumination.