On the critical competition between singlet exciton decay and free charge generation in non-fullerene based organic solar cells with low energetic offsets.

ABSTRACT: Reducing voltage losses while maintaining high photocurrents is the holy grail of current research on non-fullerene acceptor (NFA) based organic solar cell. Recent focus lies in understanding the various fundamental mechanisms in organic blends with minimal energy offsets - particularly the relationship between ionization energy offset (ΔIE) and free charge generation. Here, we quantitatively probe this relationship in multiple NFA-based blends by mixing Y-series NFAs with PM6 of different molecular weights, covering a broad power conversion efficiency (PCE) range: from 15% down to 1%. Spectroelectrochemistry reveals that a ΔIE of more than 0.3 eV is necessary for efficient photocurrent generation. Bias-dependent time-delayed collection experiments reveal a very pronounced field-dependence

SUBMITTER: Pranav M 

PROVIDER: S-EPMC11323475 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature