Guard flow-enhanced organic vapor jet printing of photovoltaic donor materials in air

► We introduce a solvent-free deposition technique (GF-OVJP) to fabricated organic photovoltaic devices in air. ► We use CFD to show the increase in shielding and energy of the organic molecules in the vapor with guard flow rate. ► Higher SubPc thin film crystallinity and lower roughness are observed at higher guard flows. ► We fabricate OPVs with the donor layer deposited in air by GF-OVJP and compared to thermally evaporated control devices. ► GF-OVJP processing parameters enable control on film morphology and resulting device performance.