Improved efficiency and stability of outdoor and indoor organic photovoltaics with suppressed voltage loss via alkoxylation on dimeric giant acceptors featured as supramolecular stabilizers

Abstract

Organic solar cells (OSCs) have shown remarkable progress in power conversion efficiencies (PCEs), largely driven by the development of small-molecule acceptors (SMAs), with PCEs of over 20%. However, their stability issue has become a critical factor that limits the commercialization of SMA-OSCs. Therefore, we developed a novel dimeric giant acceptor (DGA), named DYO-V, featuring alkoxy chains on the β-position of the outer thienothiophen, with upshifted energy levels for suppressed voltage losses. By connecting with one vinylene linker, DYO-V demonstrated a rigid and co-planar conformation, leading to a high binding energy with a high glass transition temperature for stable morphology. This DGA supramolecular stabilizer exhibited complementary absorption, durable morphology and photon dynamics to simultaneously achieve high efficiency and stability in ternary devices. Therefore, the fabricated PM6:BTP-eC9:DYO-V device achieved a PCE of 20.2%, which represents the highest PCE achieved for DGA-based OSCs with a high open-circuit voltage (V_OC) of 0.90 V and robust device stability (T₉₀ = 2000 hours). Furthermore, the hypsochromic DYO-V exhibited excellent indoor photovoltaic performance with a PCE of 28.1% for PM6:DYO-V, which is the best performance observed for DGA-indoor organic photovoltaics. Thus, this work presents an effective strategy for designing DGAs with wider bandgaps for efficient and stable outdoor and indoor photovoltaic applications.