Optimization of GaN window layer for InGaN solar cells using polarization effect

Omkar Jani, Balakrishnam Jampana, Mohit Mehta, Hongbo Yu, Ian Ferguson, Robert Opila, Christiana Honsberg

Research output: Chapter in Book/Report/Conference proceedingConference contribution

10 Scopus citations


The III-nitride material system offers substantial potential to develop high-efficiency solar cells. Theoretical modeling of InGaN solar cells indicate strong band bending at the top surface of p-InGaN junction caused due to piezoelectric polarization-induced charge at the strained p-GaN window interface. A counterintuitive strained n-GaN window layer is proposed, modeled and experimentally verified to improve performance of InGaN solar cells. InGaN solar cells with band gap of 2.9 eV are grown using MOCVD with p-type and n-type strained GaN window layers, and fabricated using variable metallization schemes. Fabricated solar cells using n-GaN window layers yield superior V OC and FF compared to those using p-GaN window layers. The V OC's of InGaN solar cells with n-GaN window layers are further enhanced from 1.5 V to 2 V by replacing the conventional NiOX top contact metal with Ti/Al, which also verifies the tunneling principle.

Original languageEnglish (US)
Title of host publication33rd IEEE Photovoltaic Specialists Conference, PVSC 2008
StatePublished - 2008
Externally publishedYes
Event33rd IEEE Photovoltaic Specialists Conference, PVSC 2008 - San Diego, CA, United States
Duration: May 11 2008May 16 2008

Publication series

NameConference Record of the IEEE Photovoltaic Specialists Conference
ISSN (Print)0160-8371


Other33rd IEEE Photovoltaic Specialists Conference, PVSC 2008
Country/TerritoryUnited States
CitySan Diego, CA

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


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