In Situ Self‐Assembly of Trichlorobenzoic Acid Enabling Organic Photovoltaics with Approaching 19% Efficiency

Abstract

Future industrialization of organic photovoltaics (OPVs) requires OPVs’ processing to be more energy‐efficient and streamlined. Currently, only MoO3 and PEDOT:PSS are commonly used as the anode interface layer (AIL). The processing of MoO3 typically involves vacuum thermal evaporation with stringent thickness requirements. PEDOT:PSS necessitates separate processing and thermal annealing at temperatures exceeding 100 °C to eliminate moisture. This work utilized 3,4,5‐trichlorobenzoic acid (3CBA) as the AIL material. The distinct advantage of 3CBA over PEDOT:PSS and MoO3 is the in situ self‐assembly of 3CBA eliminates the need for separate solution processing, thermal evaporation, or thermal annealing. Remarkably, OPV devices incorporating PM6, BTP‐eC9, and the 3CBA AIL exhibited a superior efficiency of 18.2% compared to those with PEDOT:PSS (17.7%). By using nonhalogenated solvent, o‐xylene, to meet industrialization requirements, the devices achieved an exceptional efficiency of 18.8%, the highest reported value among devices with in situ self‐assembled interface layers. Furthermore, semi‐transparent devices with 3CBA displayed higher PCE and AVT values (13.1% and 25.7%) than their PEDOT: PSS counterparts, due to the weak absorption of the 3CBA AIL. This work contributes significantly to the high‐throughput production of OPVs by streamlining the AIL processing.

Hemispherical-shell-shaped organic photovoltaic cells for absorption enhancement and improved angular coverage

“…It is envisaged that with the improved absorption and omnidirectionality characteristics, the proposed hemispherical-shell-shaped active layers will be found beneficial in various application areas of the organic solar cells (OSCs), such as biomedical devices, 32 semitransparent OSC applications, including power generation windows and greenhouses, 33,34 indoor applications, including internet-of-things (IOTs), 35 and so on.…”

Multifunctional PMMA intermediate layer for sequentially deposited organic photovoltaics

“…Over the past decade, organic photovoltaics (OPVs) have garnered significant interest due to their attractive features such as solution processability, low cost, and eco-friendliness. 1–22 Within OPVs, excitons (excitation states generated by the absorption of sunlight) migrate to the donor–acceptor interface, where they give rise to charge-transfer states, which can then dissociate into free charge carriers: holes and electrons. These charge carriers are transported through phases rich in donor and acceptor materials, respectively, culminating at the electrodes where they are harvested.…”

Novel Materials for Semi-Transparent Organic Solar Cells

“…In the past few years, there has been remarkable advancement in power conversion efficiency (PCE) for various solar cell technologies. Some of the record PCEs are 26.7% for mono-crystalline silicon [8], 24.4% for multi-crystalline silicon [9], 10.3% for hydrogenated amorphous silicon (a-Si:H) [10], 23.6% for CIGS [11], 22.3% for CdTe [12], 26.1% for Perovskite-single junction [13], 33.7% for Perovskite-2 Terminal (perovskite/Si) tandem solar cells [13], 20.6% for organic solar cells (OSCs) [14][15][16], and 14.2% for dye-sensitized solar cells [17]. Despite these advances, silicon-based photovoltaics (PV) currently dominates the market, accounting for around 95% of total commercial production.…”