Fabrication of high-density self-organized quantum dot array and control of photovoltaic conversion mechanism

2017 Fiscal Year Final Research Report

• Project/Area Number: 26246017
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Crystal engineering
• Research Institution: The University of Tokyo
• Principal Investigator: OKADA YOSHITAKA 東京大学, 先端科学技術研究センター, 教授 (40224034)
• Research Collaborator: TAMAKI RYO 東京大学, 先端科学技術研究センター, 助教 ; SHOJI YASUSHI 東京大学, 先端科学技術研究センター, 特任助教 ; YOSHIDA KATSUHISA 東京大学, 先端科学技術研究センター, 特任研究員
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 量子ドット太陽電池 / 中間バンド太陽電池 / 自己組織化量子ドット / ２段階光吸収過程 / 分子線エピタキシー

Outline of Final Research Achievements

The intermediate band solar cell is one of the most promising candidates for the next generation of photovoltaic cells with a maximum theoretical efficiency of >60% under sunlight concentration, and quantum dot based solar cells gained intense research.
In this work, type-II GaSb/AlGaAs quantum dot solar cells were investigated for application to intermediate band solar cells. Multi-stacked GaSb quantum dots were embedded in the i-region of host GaAs or AlGaAs single-junction solar cells. Fourier transform photocurrent spectroscopy with absolute intensity calibration revealed infrared external quantum efficiency spectra by two-step photon absorption. Thermionic emission of photo-carriers was suppressed efficiently in these device architectures, and significant photocurrent production via two-step photon absorption was confirmed at room temperature operation.

Free Research Field

量子ナノ構造