Molecular Structure-Intrinsic Photostability Relationships for a Series of Conjugated Polymers: Backbone Substitution Matters!

Herein,we present an efficient approach for screeningthe intrinsicphotostability of organic absorber materials used in photovoltaicapplications. Using a series of structurally related conjugated polymersand a set of complementary techniques, we established important "materialstructure-photostability" relationships. In particular,we have revealed that the introduction of alkoxy, thioalkyl, and fluorinesubstituents adversely affects the material photostability. Furthersystematic screening of different types of materials using the developedtechniques should yield a set of guidelines for designing more stableabsorber materials for organic solar cells.