Hybrid photovoltaic and electron-tunneling converters

TL;DR

This paper introduces a novel hybrid photovoltaic and electron-tunneling mechanism that reduces irreversibilities and enhances efficiency in photon-to-electron conversion, especially for high-concentration solar cells.

Contribution

It presents a new integrated model combining photovoltaic conversion with electron tunneling, improving efficiency by minimizing energy losses.

Findings

Outperforms existing models in high-concentration solar cells

Reduces irreversibilities by optimizing tunneling parameters

Provides a design guide for next-generation photon-to-electron converters

Abstract

Photon impingement is capable of liberating electrons in semiconductors. When the electron transport is primarily governed by temperature gradients, high irreversibilities will result, thus lowering converters' efficiencies. A fundamental study in the absence of photovoltaics\cite{1} has achieved the reduction of these irreversibilities by considering entropy changes due to electron flows. Here we present an unreported mechanism that integrates photovoltaic conversion and electron tunneling. Photon-excited electrons that occupy energy levels beyond windowed limits are first imprisoned inside the cathode, then given opportunities to rapidly re-thermalize, and eventually allowed to enter the tunnel. Energies wasted by both the irreversibility and the recombination are minimized with respect to the transmission energy and the transmission window that characterize the tunnel. Upon application of this mechanism to high-concentration solar cells, the proposed hybrid model outperforms others. It further provides a guide for elevating efficiencies in future photon-to-electron converters typified by third-generation photovoltaic systems.