68.9% Efficient GaAs-Based Photonic Power Conversion Enabled by Photon Recycling and Optical Resonance

被引：110

作者：

Helmers, Henning ^{[1
]}

Lopez, Esther ^{[1
]}

Hoehn, Oliver ^{[1
]}

Lackner, David ^{[1
]}

Schoen, Jonas ^{[1
]}

Schauerte, Meike ^{[1
]}

Schachtner, Michael ^{[1
]}

Dimroth, Frank ^{[1
]}

Bett, Andreas W. ^{[1
]}

机构：

[1] Fraunhofer Inst Solar Energy Syst, Fraunhofer ISE, Heidenhofstr 2, D-79110 Freiburg, Germany

来源：

PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS | 2021年 / 15卷 / 07期

关键词：

back reflectors; optical power transmission; photon recycling; photonic power converters; resonance;

D O I：

10.1002/pssr.202100113

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

For solar cells operating under the broad-band solar spectrum, the photovoltaic conversion efficiency is fundamentally limited by transmission and thermalization losses. For monochromatic light, these losses can be minimized by matching the photon energy and the absorber material's bandgap energy. Furthermore, for high-crystal-quality direct semiconductors, radiative recombination dominates the minority carrier recombination. Light-trapping schemes can leverage reabsorption of thereby internally generated photons. Such photon recycling increases the effective excess carrier concentration, which, in turn, increases photovoltage and consequently conversion efficiency. Herein, a back surface reflector underneath a GaAs/AlGaAs rear-heterojunction structure leverages photon recycling to effectively reduce radiative recombination losses and therefore boost the photovoltage. At the same time, resonance in the created optical cavity is tailored to enhance near-bandgap absorption and, thus, minimize thermalization loss. With a thin film process and a combined dielectric-metal reflector, an unprecedented photovoltaic conversion efficiency of 68.9 +/- 2.8% under 858 nm monochromatic light at an irradiance of 11.4 W cm(-2) is demonstrated.

引用

页数：7

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[1] Laser Driven Miniature Diamond Implant for Wireless Retinal Prostheses [J].