Hot Carrier Extraction Using Energy Selective Contacts and Its Impact on the Limiting Efficiency of a Hot Carrier Solar Cell

Extraction of charge carriers from a hot carrier solar cell using energy selective contacts, and the impact on limiting power conversion efficiency is analyzed. It is shown that assuming isentropic conversion of carrier heat into voltage implies zero power output at all operating points. Under conditions of power output, lower voltages than in the isentropic case are obtained due to the irreversible entropy increase associated with carrier flow. This lowers the limiting power conversion efficiency of a hot carrier solar cell.