Highly functionalized p-i-n type quantum dot based hybrid solar cells

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03536
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Energy engineering
• Research Institution: Kyoto University
• Principal Investigator: Sagawa Takashi 京都大学, エネルギー科学研究科, 教授 (20225832)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 量子ドット / 金属硫化物 / 金属酸化物 / ナノロッドアレイ / ペロブスカイト / 薄膜 / メニスカス法 / 太陽電池

Outline of Final Research Achievements

Colloidal quantum dots (CQDs) made of metal sulfides based semiconducting nanoparticles covered by small molecular organic ligands have been prepared. Suppression of charge trap and recombination at the lattice defect and/or impurity state and improvement of the contacts at the interfaces among the multicomponent in solar cells have been investigated. In particular, thin-films made of CQDs of composite metal sulfide with zinc, lead, and silver and/or lead sulfide with quasi super lattice structures in the films could be prepared by meniscus convective deposition technique in addition to partial substitution of the ligands on the CQDs. As the results, reduction of voids, enhancement of electron mobility, promotion of photocurrent generation, increase of open circuit voltage, and improvement of rectification ratio were confirmed and those effects brought increment of the power conversion efficiency in addition to the long lifetime of the devices with stable photovoltaic performance.

Free Research Field

半導体、光電変換

Academic Significance and Societal Importance of the Research Achievements

量子ドットを用いた太陽電池に関して、理論変換効率最高値と現状のギャップを埋めるために、金属硫化物半導体のナノ粒子を有機低分子化合物で被覆したコロイダル量子ドットを作製し、超格子構造に近い状態でフィルム化することと、配位子の部分置換は、格子欠陥や不純物準位でのトラップや再結合の抑制と、太陽電池を構成する他の材料との接合の不具合の解消による高機能化に有効であることを実証できたものの、依然として、上記のギャップを十分に埋めてはいない。超格子構造形成と配位子の部分置換のみならず、CsPbBr3及びその類縁化合物をはじめとする量子ドット自身の新しい部材の開拓をさらに進める必要があることも明らかとなった。