In situ formation of thermoset matrices for improved stability in organic photovoltaics

Jianhua Han; Han Xu; A. Sharma; Maxime Babics; Jules Bertrandie; Xunchang Wang; Luis Huerta Hernandez; Yongcao Zhang; Yuanfan Wen; Diego Rosas Villalva; Nicolas Ramos; Sri Harish Kumar Paleti; Jaime Martín; Fuzong Xu; Joel Troughton; Renqiang Yang; Julien Gorenflot; Frédéric Laquai; Stefaan De Wolf; Derya Baran

doi:10.1016/j.joule.2024.07.008

In situ formation of thermoset matrices for improved stability in organic photovoltaics
Artikel i vetenskaplig tidskrift, 2024

The performance of organic photovoltaics (OPVs) has rapidly increased. Yet, achieving long-term stability in the nano-morphology and thereby sustaining device performance remains challenging. Herein, we show that incorporating in-situ-forming cross-linked thermoset (CLT) matrices into the bulk heterojunction blends is a simple, general, and efficient strategy for high-performing and resilient OPVs. Our simulations and experimental data prove that these high-modulus CLT matrices featuring hydrogen-bonding interactions can freeze the nano-morphology, resulting in long-term thermal and photostable OPV devices. We demonstrate that this approach works efficiently with eight different blends and show that OPV devices can withstand 85°C for 1,000 h without losing performance. Blends with CLT matrices double the energy generated from OPV devices, showing an energy density output of 4,054 mW⋅h cm−2 over an 11-week operating period under outdoor conditions. This methodology opens avenues for both developing new thermoset networks for OPV and their use in other optoelectronic applications.

glass transition temperature

outdoor stability

thermal mechanical behavior

thermal stability

organic solar cells

dynamic mechanical analysis

hydrogen-bonding interactions

morphological stability