Thermoelectrical Field Effects in Low Dimensional Structure Solar Cells

TL;DR

This paper explores how temperature gradients in low-dimensional solar cells can be exploited to surpass traditional efficiency limits, proposing a quantitative theory and design strategies involving quantum wells and material choices.

Contribution

It introduces a quantitative theory for thermoelectrical effects in low-dimensional solar cells and suggests design modifications to significantly enhance efficiency beyond conventional limits.

Findings

Efficiency can be increased beyond the Shockley-Queisser limit due to temperature gradients.

Quantum wells can further enhance efficiency by exploiting temperature jumps at heterojunctions.

Proper material selection and device design are crucial for maximizing thermoelectrical effects.

Abstract

Taking into account the temperature gradients in solar cells, it is shown that their efficiency can be increased beyond the Shockley-Queisser limit (J. Appl. Phys. 32 (1961) 510). The driving force for this gain is the temperature gradient between this region and its surroundings. A quantitative theory is given. Though the effect is found to be weak in conventional solar cells, it is argued that it can be substantially increased by proper choice of materials and design of the device. In particular, it is shown that the insertion of a quantum well can enhance the efficiency beyond one of the single gap cell, due to the presence of temperature jumps at the heterojunctions.