High-Temperature Polarization-Free III-Nitride Solar Cells with Self-Cooling Effects

Xuanqi Huang, Wei Li, Houqiang Fu, Dongying Li, Chaomin Zhang, Hong Chen, Yi Fang, Kai Fu, Steven P. Denbaars, Shuji Nakamura, Stephen Goodnick, Cun Zheng Ning, Shanhui Fan, Yuji Zhao

Research output: Contribution to journalArticlepeer-review

29 Scopus citations


High-temperature photovoltaics (PV) for terrestrial and extraterrestrial applications have presented demanding challenges for current solar cell materials, such as Si, III-V AlGaInP, and II-VI. Wide-bandgap III-nitride materials, in contrast, offer several intrinsic advantages that make them extremely appealing for high-temperature applications. In this study, we fabricated and characterized III-nitride solar cells using polarization-free (i.e., nonpolar) InGaN/GaN multiple quantum wells (MQWs). The InGaN solar cells showed a large working temperature range from room temperature (RT) to 450 °C, with positive temperature coefficients up to 350 °C. The peak external quantum efficiencies of the devices showed a 2.5-fold enhancement from RT (∼32%) to 450 °C (∼81%), which is distinct from all other solar cells ever reported. This can be partially attributed to an increase of over 70% in carrier lifetime in nonpolar InGaN MQWs obtained from time-resolved photoluminescence. Furthermore, a thermal radiation analysis revealed a unique self-cooling effect for III-nitride materials, which also helps enhance device performance at high temperature. These results offer new insights and strategies for the design and fabrication of high-efficiency high-temperature PV cells.

Original languageEnglish (US)
Pages (from-to)2096-2103
Number of pages8
JournalACS Photonics
Issue number8
StatePublished - Aug 21 2019


  • III-nitrides
  • high temperature
  • polarization-free
  • self-cooling
  • solar cells

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering
  • Biotechnology


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