Evaluation of defects of epitaxial thin film in multinary compound semiconductors

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01833
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 30010:Crystal engineering-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Tampo Hitoshi 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 主任研究員 (20392631)
• Co-Investigator(Kenkyū-buntansha): 永井 武彦 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 主任研究員 (70415719)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 化合物半導体 / 多元系化合物 / 太陽電池

Outline of Final Research Achievements

The objective of this study was to propose a new and simple method to evaluate VOCs using PL emission intensity as an alternative to PL emission lifetime measurement, and to theoretically and experimentally demonstrate the relationship between PL intensity and photovoltaic characteristics with a focus on VOCs. As the target solar cell, we utilized a structure with a quatenary compound Cu2ZnSnS4 (CZTS) as the light-absorbing layer. First, we theoretically established a proportional relationship between PL luminescence intensity and TRPL luminescence lifetime. Then, we experimentally characterized the solar cells and subsequently showed that there is a linear relationship between PL intensity and TRPL luminescence lifetime. This result indicates that the open circuit voltage can be evaluated by PL intensity and can be widely used in various solar cell systems.

Free Research Field

半導体工学

Academic Significance and Societal Importance of the Research Achievements

本研究は、太陽電池の特性について太陽電池を作製しなくても光学的（photoluminesce：PLの発光強度）に評価できることを、理論的および実験的に示した。太陽電池作製には時間も労力も要するが、本手法によりそれらを経ず太陽電池材料としてのポテンシャル評価に利用できる手法を提供するものである。従来法では、時間分解PL法を利用しており、特別な措置が必要である場合や、その解釈で困難があったがその観点からも本手法は意義深い。