Development of the very high efficiency thin-film multiple quantum well solar cells

• Project/Area Number: 26630107
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Power engineering/Power conversion/Electric machinery
• Research Institution: The University of Tokyo
• Principal Investigator: Watanabe Kentaroh 東京大学, 先端科学技術研究センター, 特任講師 (30523815)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2015: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2014: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
• Keywords: 半導体 / III-V族化合物 / 太陽電池 / 量子井戸 / 定量光学評価 / MOCVD / エピタキシャル成長 / III-V族化合物半導体 / 量子構造 / エピタキシャルリフトオフ / フォトルミネッセンス / エレクトロルミネッセンス / 化合物半導体 / 多重量子井戸 / 超格子 / CPV / 薄膜III-V族セル / 集光型太陽光発電 / 低コスト化

Outline of Final Research Achievements

In this research, we tried to fabricate the thin-film GaAs single junction solar cell with multiple quantum wells inserted in i-region of p-i-n structure. The fabrication process of the thin-film MQW solar cell was developed by transferring epitaxially grown PV active layer to the support substrate by selective wet etching with the InGaP etch-stop layer. Additional grating pattern and high-reflective mirror on the rear surface of thin-film MQW solar cell enhanced the light trapping effect, resulted in over 5 times larger effective optical path length than the physical thickness. Optical characterization of the thin-film MQW solar cell was also attempted to analyze the quasi-Fermi level splitting. Owing to the quantitative electroluminescence (EL) measurement, the internal radiative efficiency can be estimated to the thin-film MQW solar cell. This result indicated that the MQW increased a probability of radiative recombination inside the cell than the bulk GaAs cell.

Research Products

• [Journal Article] Thin-film solar cells with InGaAs/GaAsP multiple quantum wells and a rear surface etched with light trapping micro-hole array (2015)
  • Author(s): Kentaroh Watanabe, Tomoyuki Inoue, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano
  • Journal Title: Jpn. J. Appl. Phys. Volume: 54 Issue: 8S1 Pages: 08KA13-08KA13
  • DOI: 10.7567/jjap.54.08ka13
  • Peer Reviewed
• [Journal Article] Enhanced Light Trapping in Multiple Quantum Wells by Thin-Film Structure and Backside Grooves With Dielectric Interface (2015)
  • Author(s): Tomoyuki Inoue, Kentaroh Watanabe, Kasidit Toprasertpong, Hiromasa Fujii, Masakazu Sugiyama, and Yoshiaki Nakano
  • Journal Title: IEEE J. Photovoltics Volume: 5 Issue: 2 Pages: 697-703
  • DOI: 10.1109/jphotov.2015.2392941
  • Peer Reviewed
• [Journal Article] Absorption enhancement trough Fabry-Peort resonant modes in a 430 nm thick InGaAs/GaAsP multiple quantum wells solar cell (2015)
  • Author(s): B. Behaghel, R. Tamaki, N. Vandamme, K. Watanabe, C. Dupuis, N. Bardou, H. Sodabanlu, A. Cattoni, Y. Okada, M. Sugiyama, S. Collin, and J.-F. Gulliemoles
  • Journal Title: Appl. Phys. Lett. Volume: 106 Issue: 8
  • DOI: 10.1063/1.4913469
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Thin-Film InGaAs/GaAsP MQWs Solar Cell With Backside Nanoimprinted Pattern for Light Trapping (2014)
  • Author(s): Kentaroh Watanabe, Boram Kim, Tomoyuki Inoue, Hassanet Sodabanlu, Masakazu Sugiyama, Masanao Goto, Shinya Hayashi, Kenjiro Miyano, Yoshiaki Nakano
  • Journal Title: IEEE Journal of Photovoltaics Volume: 4 Issue: 4 Pages: 1086-1090
  • DOI: 10.1109/jphotov.2014.2312486
  • Peer Reviewed
• [Presentation] Optical analysis of the photon recycling effect in InGaAs/GaAsP multiple quantum well solar cell with light trapping structure (2016)
  • Author(s): Kentaroh Watanabe, Tomoyuki Inoue, Kasidit Toprasertpong, Amaury Delamarre, Hassanet Sodabanlu, Jean-Francois Guillemoles, Masakazu Sugiyama, Yoshiaki Nakano
  • Organizer: 43rd IEEE Photovoltaic Specialist Conference
  • Place of Presentation: Portland, OR, USA
  • Year and Date: 2016-06-05
  • Int'l Joint Research
• [Presentation] Quasi-Fermi level splitting evaluation based on electroluminescence analysis in multiple quantum well solar cells for investigating cell performance under concentrated light (2016)
  • Author(s): T. Inoue, K. Toprasertpong, A. Delamarre, K. Watanabe, M. Paire, L. Lombez, J-F. Guillemoles, M. Sugiyama, and Y. Nakano
  • Organizer: SPIE Photonics West
  • Place of Presentation: San Francisco, CA, USA
  • Year and Date: 2016-02-13
  • Int'l Joint Research
• [Presentation] Spatial carrier collection efficiency imaging by luminescence (2015)
  • Author(s): Amaury Delamarre, Laurent Lombez, Kentaroh Watanabe, Masakazu Sugiyama, Jean-Francois Guillemoles
  • Organizer: 25th International Photovoltaic Science and Engineering Conference
  • Place of Presentation: Busan, Korea
  • Year and Date: 2015-11-15
  • Int'l Joint Research
• [Presentation] Self-Organized Texture of GaAs by Wet etching for Light Trapping in MQWs Solar Cells (2015)
  • Author(s): K. Watanabe,T. Inoue, M. Sugiyama, and Y. Nakano
  • Organizer: 31st European Photovoltaic Solar Energy Conference and Exhibition
  • Place of Presentation: Hamburg, Germany
  • Year and Date: 2015-09-30
  • Int'l Joint Research
• [Presentation] Thin-film InGaAs/GaAsP MQWs Solar Cell with Dielectric Micro-Hole Array Structure for Light Trapping Effect (2014)
  • Author(s): Kentaroh Watanabe, Tomoyuki Inoue, Hassanet Sodabanlu, Masakazu Sugiyama, Yoshiaki Nakano
  • Organizer: WCPEC-6
  • Place of Presentation: 京都国際会館
  • Year and Date: 2014-11-23 – 2014-11-27
• [Presentation] Enhanced Light Trapping in Multiple Quantum Wells by Thin Film Structure and Backside Grooves with Dielectric Interface (2014)
  • Author(s): Tomoyuki Inoue, Kentaroh Watanabe, Masakazu Sugiyama, Yoshiaki Nakano
  • Organizer: IEEE PVSC40
  • Place of Presentation: Denver, Colorado, USA
  • Year and Date: 2014-06-08 – 2014-08-13