Voltage deficit in solar cells with suppressed recombination

TL;DR

This paper proposes that suppressed recombination, influenced by electrostatic effects and nonuniformities, explains the open circuit voltages in high-performance solar cells, challenging traditional recombination-based models.

Contribution

It introduces the concept of suppressed recombination as an alternative pathway to efficient photovoltaic performance, supported by data analysis.

Findings

Open circuit voltage deficit has a lower bound of 0.2-0.3 V.

Best performing solar cells' voltages are explained outside the recombination paradigm.

Voltage deficit does not correlate with optical gap and varies among similar materials.

Abstract

The observed open circuit voltages in best performing solar cells are explained outside of the recombination paradigm, based on such factors as electrostatic screening, Meyer-Neldel effect, and lateral nonuniformities. The underlying concept of suppressed recombination presents a long neglected alternative pathway to efficient PV. The criterion of suppressed recombination is consistent with the data for best performing solar cells. Also, consistent with the observations, is the open circuit voltage deficit that exhibits a lower bound of about $0.2-0.3$ V, does not correlate well with the optical gap, and shows a significant dispersion for materials possessing the same gap values.