Designing a Concentrated High-Efficiency Thermionic Solar Cell Enabled by Graphene Collector

Xin Zhang; Xiaohang Chen; Jinchan Chen; Lay Kee Ang; Yee Sin Ang

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arXiv · 2102.03294

Designing a Concentrated High-Efficiency Thermionic Solar Cell Enabled by Graphene Collector

Xin Zhang·Xiaohang Chen·Jinchan Chen·Lay Kee Ang·Yee Sin Ang

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Abstract

We propose a concentrated thermionic emission solar cell design, which demonstrates a high solar-to-electricity energy conversion efficiency larger than 10\% under 600 sun, by harnessing the exceptional electrical, thermal and radiative properties of the graphene as a collector electrode. By constructing an analytical model that explicitly takes into account the non-Richardson behavior of the thermionic emission current from graphene, space charge effect in vacuum gap, and the various irreversible energy losses within the subcomponents, we perform a detailed characterization on the conversion efficiency limit and electrical power output characteristics of the proposed system. We systematically model and compare the energy conversion efficiency of various configurations of graphene-graphene and graphene-diamond and diamond-diamond thermionic emitter, and show that utilizing diamond films as an emitter and graphene as a collector offers the highest maximum efficiency, thus revealing the important role of graphene in achieving high-performance thermionic emission solar cell. A maximum efficiency of 12.8\% under 800 sun has been revealed, which is significantly higher than several existing solid-state solar cell designs, such as the solar-driven thermoelectric and thermophotovoltaic converters. Our work thus opens up new avenues to advance the efficiency limit of thermionic solar energy conversion and the development of next-generation novel-nanomaterial-based solar energy harvesting technology.

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Xin Zhang, Xiaohang Chen, Jinchan Chen, Lay Kee Ang, Yee Sin Ang. 2021-02-05. Designing a Concentrated High-Efficiency Thermionic Solar Cell Enabled by Graphene Collector. https://arxiv.org/abs/2102.03294

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