Challenge to the realization of dopant-free flexible solar cells that expand the application area of photovoltaics

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K20998
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 21:Electrical and electronic engineering and related fields
• Research Institution: Nagoya University
• Principal Investigator: Usami Noritaka 名古屋大学, 工学研究科, 教授 (20262107)
• Project Period (FY): 2020-07-30 – 2022-03-31
• Keywords: 太陽電池 / 光閉じ込め構造 / ヘテロ接合 / 結晶シリコン / ドーパントフリー / 酸化チタン / 窒化チタン

Outline of Final Research Achievements

We developed fundamental processes to realize dopant-free flexible solar cells with metal/titanium oxide/crystalline silicon heterojunctions with high passivation and low resistance. Specifically, the process includes pre-oxidation treatment of crystalline silicon, formation of titanium oxide thin film by atomic layer deposition, the introduction of a titanium nitride intermediate layer on the titanium oxide thin film, and deposition of a metal thin film. In addition, as a formation technology of light-trapping nanotextures on the ultra-thin silicon substrates that exhibit flexibility, we have devised a simple solution process that only requires adding a solution to form metal nanoparticles on the surface of crystalline silicon and surfactant in the conventional alkaline solution.

Free Research Field

応用物性・結晶工学

Academic Significance and Societal Importance of the Research Achievements

本研究では、ドーパントを用いずに高効率太陽電池の要件を満たす新たな接合として、金属酸化物と結晶シリコンのヘテロ接合の研究を進め、界面の精緻な制御によりpn接合を凌駕する高性能化の可能性を示した。また、フレキシブル性の発現する薄い結晶シリコンにも適用可能な光閉じ込めのためのテクスチュア構造の形成技術を開発した。これらは、太陽電池の新用途開拓など、さらなる大規模普及や社会の脱炭素化を加速する技術への貢献が期待される。