Fabrication of higher-manganese-silicide thin films for near-infrared absorption solar cells

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K18971
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Materials engineering and related fields
• Research Institution: Tohoku University
• Principal Investigator: Hayashi Kei 東北大学, 工学研究科, 准教授 (70360625)
• Research Collaborator: ISHII kentaro ; KAWASAKI chihiro ; HONDA ryosuke ; YANG runchen
• Project Period (FY): 2017-06-30 – 2019-03-31
• Keywords: 太陽電池

Outline of Final Research Achievements

We measured optical bandgap and carrier density of Mn1-xFexSig~1.73. Mn1-xFexSig~1.73 thin films were fabricated by using a pulsed laser deposition method. The optical bandgap of Mn1-xFexSig~1.73 thin films was approximately 0.8 eV, which was in the near-infrared (NIR) energy range. The carrier density of a Mn1-xFexSig~1.73 bulk sample (x = 0.28) was approximately 1×10{17} cm-3, which was enough to absorb NIR light up to 90%. To fabricate p-n junction of Mn1-xFexSig~1.73, we attempted to prepare a Mn1-xFexSig~1.73 single crystal that can be used as a substrate, by means of a melt-grown method. Mn1-xFexSig~1.73 single crystals were successfully obtained in the range of x < 0.2. Using the p-type Mn1-xFexSig~1.73 single crystal (x = 0.15), we could grow n-type Mn1-xFexSig~1.73 thin films.

Free Research Field

太陽電池、熱電変換

Academic Significance and Societal Importance of the Research Achievements

本研究により、マンガンシリサイド(Mn1-xFexSiγ~1.73)薄膜を用いて、近赤外光利用太陽電池を開発できることが明らかになった。現在普及している太陽電池は近赤外光をエネルギー源として用いておらず、太陽光エネルギーから電気エネルギーに変換するエネルギー変換効率は約20%である。現状の薄膜太陽電池とp型、n型マンガンシリサイド(Mn1-xFexSiγ~1.73)の薄膜太陽電池を組み合わせれば、エネルギー変換効率を約30%まで向上できると予想される。