Fabrication of novel solar cell using ferroelectric polarization in Fe-based perovskite oxide

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06256
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Electronic materials/Electric materials
• Research Institution: Kanazawa University
• Principal Investigator: MORIMOTO Akiharu 金沢大学, 電子情報通信学系, 教授 (60143880)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 強誘電体薄膜 / 電気分極誘起光起電力 / 希土類・遷移金属置換 / パルスレーザー堆積 / 酸素欠損の影響 / 膜厚依存性

Outline of Final Research Achievements

Solar cell using ferroelectric perovskite thin film with mechanism different from conventional photovoltaic effect has attracted much attention. We originally fabricated Nd-doped BiFeO3 (BNF) sample and performed characterization of the photovoltaic properties.
So far, we have fabricated BNF film on expensive single-crystal Nb:STO substrate. In the present study we fabricated BNF film solar cell using the pulse laser deposition on inexpensive Pt/Si substrate. Then we obtained an excellent photovoltaic property on the sample with Pt/Si substrate, comparable to that on the sample with Nb:STO substrate. Furthermore, we improved photovoltaic properties by the annealing of this sample and obtained a photovoltaic property superior to a single-crystal sample. In addition, we showed that photovoltaic properties are caused by the electric polarization of the ferroelectric film from the BNF film thickness-dependence investigation.

Free Research Field

電子・電気材料工学

Academic Significance and Societal Importance of the Research Achievements

従来の光起電力効果と異なる強誘電体ペロブスカイト薄膜太陽電池の課題は、その光起電力特性の起源を明らかにし、光起電力特性を改善することである。我々独自のNdで置換したBiFeO3系（BNF）太陽電池は、多くの強誘電体太陽電池の中でもその性能が高く、この試料を低コストのPt/Si基板上で実現し性能を改善したことは太陽電池応用には重要である。また、この光起電力が強誘電体薄膜の強誘電性分極誘起反電界モデルでかなり説明可能なことを示したことは、太陽電池応用のみならず、並行して進めているのほぼ同等構造の強誘電体抵抗スイッチングメモリFe-ReRAMのメモリ機構解明にも大いに貢献することが期待される。