Study of multi-band solar cells using dilute nitride semiconductors

• Project/Area Number: 16H05895
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Design and evaluation of sustainable and environmental conscious system
• Research Institution: Saitama University
• Principal Investigator: Yagi Shuhei 埼玉大学, 理工学研究科, 准教授 (30421415)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥24,440,000 (Direct Cost: ¥18,800,000、Indirect Cost: ¥5,640,000); Fiscal Year 2018: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000); Fiscal Year 2017: ¥9,750,000 (Direct Cost: ¥7,500,000、Indirect Cost: ¥2,250,000); Fiscal Year 2016: ¥11,960,000 (Direct Cost: ¥9,200,000、Indirect Cost: ¥2,760,000)
• Keywords: 中間バンド型太陽電池 / 希釈窒化物混晶半導体 / 希釈窒化物半導体 / 分子線エピタキシー / 太陽電池 / Ⅲ-Ⅴ族化合物 / 再生可能エネルギー / ナノ材料 / 超格子 / 半導体物性 / 結晶成長 / 高効率太陽電池 / 半導体超格子 / 高効率太陽光発電材料・素子 / 光物性

Outline of Final Research Achievements

This research was conducted for the purpose of developing high-efficiency intermediate-band (multi-band) solar cells based on a superlattice in which nitrogen delta-doped layers are inserted into a host material such as GaAs.
Samples with various alloy compositions and superlattice parameters were fabricated by MBE. They revealed the dependence of the band edge energy on the structural parameters. Physical characteristics important for designing the solar cell such as electron mobility and absorption coefficient were also obtained.
Fabricated cell showed current generation originating from two-step optical transitions via the intermediate band under two wavelength light illumination. It was found that designing a carrier blocking layer to optimize carrier accumulation in the intermediate-band and carrier extraction from the conduction band is important to enhance the current generation via the two-step optical transition.

Academic Significance and Societal Importance of the Research Achievements

太陽電池の変換効率を向上することはモジュールコスト削減や利用用途の拡大に有効であり、地球規模の環境保護の点から求められている太陽光発電の大規模普及の促進に資する。本課題では、複数バンドギャップ間の光学遷移を利用して変換効率を高める、中間バンド型太陽電池を対象に研究を行った。これまで量子ドット積層配列で形成される超格子ミニバンドを中間バンドとする方式が主流であったが、本研究では希釈窒化物半導体材料のもつ特異なバンド構造を利用することで、中間バンドの状態密度をより高め、動作上重要な2段階の光吸収の増強を試みた。特に窒素添加手法にδドープ技術を応用することで、材料品質や組成分布の制御性を改善した。

Research Products

• [Journal Article] Spectral change of E－ band emission in a GaAs:N δ-doped superlattice due to below-gap excitation and its discrimination from thermal activation (2020)
  • Author(s): Md. D. Haque, N. Kamata, A.Z.M.T. Islam, S. Yagi, and H. Yaguchi
  • Journal Title: J. Electronic Materials Volume: 49 Issue: 2 Pages: 1550-1555
  • DOI: 10.1007/s11664-019-07856-6
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Photoluminescence characterization of nonradiative recombination centers in MOVPE grown GaAs:N δ-doped superlattice structure (2019)
  • Author(s): Haque Md Dulal、Kamata Norihiko、Islam A.Z.M. Touhidul、Honda Zentaro、Yagi Shuhei、Yaguchi Hiroyuki
  • Journal Title: Optical Materials Volume: 89 Pages: 521-527
  • DOI: 10.1016/j.optmat.2019.01.047
  • Peer Reviewed
• [Journal Article] Nonradiative recombination centers in GaAs:N δ-doped superlattice revealed by two-wavelength-excited photoluminescence (2018)
  • Author(s): Dulal Haque Md.、Kamata Norihiko、Fukuda Takeshi、Honda Zentaro、Yagi Shuhei、Yaguchi Hiroyuki、Okada Yoshitaka
  • Journal Title: Journal of Applied Physics Volume: 123 Issue: 16 Pages: 161426-161426
  • DOI: 10.1063/1.5011311
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Spectral change of intermediate band luminescence in GaP:N due to below-gap excitation: Discrimination from thermal activation (2016)
  • Author(s): N. Kamata, M. Suetsugu, D. Haque, S. Yagi, H. Yaguchi, F. Karlsson, P.O. Holtz
  • Journal Title: Physica Stat. Solidi. B Volume: 254 Issue: 2 Pages: 1600566-1600566
  • DOI: 10.1002/pssb.201600566
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Optical Characterization of Nonradiative Centers in GaAs:N δ-Doped Superlattices by Using Below-Gap Excitation Light (2019)
  • Author(s): M.D. Haque, N. Kamata, A.Z.M.T. Islam, Md. Julkarnain, S. Yagi, H. Yaguchi, and Y. Okada
  • Organizer: International Conference on Computer, Communication, Chemical, Materials and Electronic Engineering (IC4ME2), Rajshahi
  • Int'l Joint Research
• [Presentation] Optical Detection of Nonradiative Recombination Levels via Intermediate Band in GaAs:N δ-Doped Superlattices (2019)
  • Author(s): N. Kamata, K. Nagata, Md. D. Haque, Z. Honda, S. Yagi, H. Yaguchi, and Y. Okada
  • Organizer: 30th International Conference on Defects in Semiconductors (ICDS30)
  • Int'l Joint Research
• [Presentation] InGaAs:N δドープ超格子の電気特性評価 (2019)
  • Author(s): 米野 龍司、宮下 直也、岡田 至崇、八木 修平、矢口 裕之
  • Organizer: 第80回応用物理学会秋季学術講演会, 札幌
• [Presentation] 窒素δ-ドープGaAs超格子の二波長励起フォトルミネッセンス法によるキャリア再結合準位評価 (2019)
  • Author(s): 永田 航太、鎌田 憲彦、八木 修平、矢口 裕之
  • Organizer: 第80回応用物理学会秋季学術講演会, 札幌
• [Presentation] (111)基板上に作製した窒素δドープGaAs中の単一等電子トラップによる励起子分子発光 (2019)
  • Author(s): 高岡 祥平、高宮 健吾、八木 修平、挟間 優治、秋山 英文、矢口 裕之
  • Organizer: 第80回応用物理学会秋季学術講演会, 札幌
• [Presentation] 第一原理計算によるGaAsN混晶中のN原子配置のバンド構造への影響の検討 (2018)
  • Author(s): 塚原悠太、 八木修平、 矢口裕之
  • Organizer: 第79回応用物理学会秋季学術講演会
• [Presentation] 二波長励起PL測定によるGaPN混晶のアップコンバージョン発光特性評価 (2018)
  • Author(s): 高橋渉、 高宮健吾、 八木修平、 狭間優治、 秋山英文、 矢口裕之、 鎌田憲彦
  • Organizer: 第79回応用物理学会秋季学術講演会
• [Presentation] Growth of InGaAs:Nδ-doped superlattices for multi-junction solar cells (2018)
  • Author(s): Shumpei Umeda, Shuhei Yagi, Naoya Miyashita, Yoshitaka Okada, Hiroyuki Yaguchi
  • Organizer: 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC2018)
  • Int'l Joint Research
• [Presentation] n型GaAs:N δドープ超格子の電気的特性評価 (2017)
  • Author(s): 加藤 諒, 八木 修平, 岡田 至崇, 矢口 裕之
  • Organizer: 第64回応用物理学会春季学術講演会
  • Place of Presentation: パシフィコ横浜（神奈川県）
  • Year and Date: 2017-03-14
• [Presentation] 1 eV帯InGaAs:N δドープ超格子の作製 (2017)
  • Author(s): 梅田 俊平, 八木 修平, 宮下 直也, 岡田 至崇, 矢口 裕之
  • Organizer: 第64回応用物理学会春季学術講演会
  • Place of Presentation: パシフィコ横浜（神奈川県）
  • Year and Date: 2017-03-14
• [Presentation] Properties of Dilute Nitride Pseudo-Alloys Grown using a Nitrogen Delta-Doping Technique (2017)
  • Author(s): S. Yagi, Y. Okada and H. Yaguchi
  • Organizer: SPIE Photonics West 2017
  • Place of Presentation: San Francisco （USA）
  • Year and Date: 2017-01-28
  • Int'l Joint Research / Invited
• [Presentation] Electrical characterization of n-type GaAs:N δ-doped superlattices (2017)
  • Author(s): Ryo Kato, Shuhei Yagi, Yoshitaka Okada, and Hiroyuki Yaguchi
  • Organizer: Compound Semiconductor Week 2017
  • Int'l Joint Research
• [Presentation] Nanostructured Dilute Nitride Alloys for High-Efficiency Solar Cells (2017)
  • Author(s): Shuhei Yagi, Yoshitaka Okada, and Hiroyuki Yaguchi
  • Organizer: International Symposium on Novel Energy Nanomaterials, Catalysts and Surfaces for Future Earth
  • Int'l Joint Research / Invited
• [Presentation] Influence of Nitrogen Atomic Arrangement in GaAsN Alloys on Band Gap Energy (2017)
  • Author(s): Kazuki Miyajima, Shuhei Yagi, Yasushi Shoji, Yoshitaka Okada, Hiroyuki Yaguchi
  • Organizer: 27th International Photovoltaic Science and Engineering Conference
  • Int'l Joint Research
• [Presentation] First-Principles Study of Optical Transitions in Gallium Arsenide:Nitrogen Delta-Doped Superlattices (2017)
  • Author(s): Hiroki Yoshikawa, Shuhei Yagi, Hiroyuki Yaguchi
  • Organizer: 27th International Photovoltaic Science and Engineering Conference
  • Int'l Joint Research
• [Presentation] GaPN混晶のアップコンバージョン発光 (2017)
  • Author(s): 高橋 渉、高宮 健吾、八木 修平、伊藤 隆、秋山 英文、矢口 裕之
  • Organizer: 第78回応用物理学会秋季学術講演会
• [Presentation] 希釈窒化物半導体中の窒素原子配置によるバンドギャップへの影響 (2017)
  • Author(s): 宮島 数喜、八木 修平、庄司 靖、岡田 至崇、矢口 裕之
  • Organizer: 第78回応用物理学会秋季学術講演会
• [Presentation] Effect of Carrier Blocking Layer on Carrier Collection in Intermediate-Band Solar Cells using GaAs:N Delta-Doped Superlattice (2016)
  • Author(s): T. Suzuki, S. Yagi, Y. Okada, H. Yaguchi
  • Organizer: 26th Photovoltaic Science and Engineering Conference (PVSEC-26)
  • Place of Presentation: Singapore
  • Year and Date: 2016-10-24
  • Int'l Joint Research
• [Presentation] レーザ照射によるGaInNAs混晶半導体の発光効率への影響 (2016)
  • Author(s): 米倉 成一, 高宮 健吾, 八木 修平, 上田 修, 矢口 裕之
  • Organizer: 第77回応用物理学会秋季学術講演会
  • Place of Presentation: 朱鷺メッセ（新潟県）
  • Year and Date: 2016-09-13