Material conversion of organo metal perovskites by hybridization of meso-stuctures

2018 Fiscal Year Final Research Report

• Project/Area Number: 26289265
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Structural/Functional materials
• Research Institution: Toin University of Yokohama
• Principal Investigator: Miyasaka Tsutomu 桐蔭横浜大学, 医用工学部, 特任教授 【東京大学先端科学技術研究センター・フェロー】 (00350687)
• Project Period (FY): 2014-04-01 – 2019-03-31
• Keywords: 有機無機ハイブリッド / ペロブスカイト / 光物性 / 光電変換 / ビスマス / 銀

Outline of Final Research Achievements

Perovskite crystals using silver (Ag) and bismuth (Bi) as cations in place of lead were synthesized and their crystal structure and optical properties were investigated. The characteristics of light emission and photoelectric conversion were evaluated. The organic-inorganic hybrid type composition (CH3NH3) 3Bi2I9 was deposited as a flat film with few physical defects by the solvent vapor annealing method. In addition, AgBi2I7 having an all-inorganic composition was synthesized by optimizing the solvent for crystallization to form a flat film with minimal physical defects. Photovoltaic devices using these lead-free perovskites were fabricated. The AgBi2I7 device with an undoped P3HT achieved a conversion efficiency of 2.2% or more. It was revealed by the durability test that these devices are considerably excellent in heat resistance and moisture resistance.

Free Research Field

光電気化学、ペロブスカイト太陽電池

Academic Significance and Societal Importance of the Research Achievements

環境に有害な鉛を組成に用いないペロブスカイト材料を設計し、その光電変換性能を高める可能性に挑む研究は、環境安全性の点において一般国民が望むテーマであり、本研究のように生体適合性をもつ銀とビスマスを金属に用いるペロブスカイト光電変換素子の高性能化は、社会の期待に向けて無鉛型ペロブスカイト材料を用いる素子の将来発展性を示すことができる点で大きな意義を持つ。学術的には、化学的プロセスである溶液晶析法を改善することによって物理欠陥をいかに抑えて質の高い製膜を達成できるかの手法をいくつか提案することができたことで、無鉛組成のペロブスカイトの光物性を高めていくことの技術基盤を提供できたと考える。