Figure 3: Device architecture and photovoltaic performances.

(a) Schematic diagram of a normal cell architecture used in this study. (b) J–V characteristics of BTR:PC₇₁BM BHJ solar cells with or without THF solvent vapour annealing tested in air under 98 mW cm⁻² AM1.5G illumination. Inset: dark current plotted in a semi-log scale of the two solar cells. (c) EQE spectra of optimized BTR-based solar cells with or without THF SVA treatment. (d) J–V curve of the most efficient BTR:PC₇₁BM BHJ solar cell after 15 s of THF SVA measured by an independent research institute in nitrogen atmosphere under an illumination of 100 mW cm⁻².