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

TL;DR

This paper analyzes how energy selective contacts affect hot carrier solar cell efficiency, revealing that irreversibility and entropy increase lower the maximum achievable power conversion efficiency.

Contribution

It provides a theoretical analysis of charge extraction mechanisms and their impact on the efficiency limits of hot carrier solar cells.

Findings

Isentropic conversion implies zero power output.

Irreversible entropy increases reduce efficiency.

Lower voltages are obtained under realistic power output conditions.

Abstract

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.