Investigating limitations in new materials for perovskite solar cells
by Riko Seibo
Tokyo, Japan (SPX) Nov 07, 2024

Perovskite solar cells, celebrated for their efficient light-to-electricity conversion, are being studied as promising next-generation solar technology. However, commonly used hole-transport materials such as spiro-OMeTAD present challenges due to their complex synthesis processes and high costs.

Addressing these issues, researchers have developed an alternative: HND-2NOMe, which is easier and more economical to synthesize.

HND-2NOMe's quasi-planar molecular structure facilitates one-dimensional alignment and promotes charge transfer. Despite its high charge mobility, solar cells using HND-2NOMe have shown performance limitations, including reduced current flow, whose cause had remained unclear.

University of Tsukuba researchers employed electron spin resonance (ESR) to explore these performance challenges by analyzing the material's microscopic properties. They discovered that, without illumination, holes migrate from the perovskite to HND-2NOMe, creating an energetic barrier at their interface.

This barrier obstructs the movement of holes, contributing to the observed performance issues. Additionally, under solar irradiation, cells incorporating HND-2NOMe showed reduced hole accumulation, aiding in the stability of the material's hole transport function.

This identification of performance-limiting factors, while preserving stability, offers significant insights for developing guidelines that could improve device performance. The research paves the way for future advancements in perovskite solar cell technology.

Research Report:Microscopic analysis of low but stable perovskite solar cell device performance using electron spin resonance.

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