# Blade-Coated All-Polymer Organic Solar Cells with 15% Efficiency Using Eco-Friendly Solvent Systems

## TL;DR

Researchers created efficient, eco-friendly organic solar cells using a scalable coating method and green solvents, achieving 15% efficiency.

## Contribution

First scalable fabrication of PM6:PY-IT all-polymer solar cells using eco-friendly o-xylene and doctor-blade coating at ambient conditions.

## Key findings

- Achieved 15% power conversion efficiency using PM6:PY-IT with green solvents and doctor-blade coating.
- Optimized film morphology and crystallinity confirmed via AFM, TEM, and GIWAXS.
- Ambient processing and scalable techniques demonstrated potential for sustainable manufacturing.

## Abstract

Organic solar cells (OSCs) offer distinct advantages,
such as solution
processability, mechanical flexibility, and semitransparency. Recent
advancements in polymerized small-molecule acceptors (PSMAs) enable
high efficiencies in all-polymer solar cells (all-PSCs). As a promising
candidate for next-generation organic photovoltaics, all-PSC technology
holds a strong potential for large-scale commercialization, provided
that device performance aligns with market demands. Critical factors
influencing this transition include the development of environmentally
friendly fabrication methods, as well as the optimization of active
layer morphology and enhancement of charge transport layer quality.
Currently, spin-coating is the predominant method for fabricating
small-area OSCs, though it typically relies on toxic solvents, limiting
its scalability and environmental compatibility. In this work, we
report, for the first time, the scalable fabrication of PM6:PY-IT
devices using the green solvent o-xylene and doctor-blade
coating at ambient temperature in air. The resulting devices, fabricated
in a conventional architecture incorporating PEDOT:PSS and PDINN interlayers,
exhibited a short-circuit current density (J
sc) of 22.54 mA/cm2, an open-circuit voltage (V
oc) of 0.91 V, and a fill factor (FF) of 67.2%
yielding a power conversion efficiency (PCE) of 15%. Key ink formulation
steps, including controlled heating, stirring, and vortexing, enabled
the optimization of film morphology and crystallinity, as confirmed
by atomic force microscopy (AFM), transmission electron microscopy
(TEM), and grazing-incidence wide-angle X-ray scattering (GIWAXS).
Charge transport properties were subsequently evaluated via the space-charge
limited current (SCLC) method. The combination of ambient, low-energy
processing, and scalable deposition techniques underscores the potential
of this approach for sustainable and efficient manufacturing of all-PSC
devices.