Morphological Stability of Organic Photovoltaics: Coarse‐grained Molecular Dynamics Simulation Studies

Abstract

We have performed coarse-grained molecular dynamics simulations of organic photovoltaic (OPV) 5wcells consisting of poly(3-hexyl-thiophene) (P3HT), phenyl-C61-butyric acid methyl ester (PC61BM), and phenyl-C71-butyricacid methyl ester (PC71BM) to investigate the effects of the solvent evaporation rate and the number of components in the morphological stability of OPV. Two different solvent evaporation processes were employed in this study. In the instantaneous solvent removal process, unstable pores are formed because of the slow translational relaxation of the electron receptors. In case of the gradual solvent removal process, the stable film formation is observed without any pore. In addition, the ternary OPV system shows better stability than binary systems by slowing down the phase separation.

Side‐chain engineering of regioregular copolymers for high‐performance polymer solar cells processed with nonhalogenated solvents

“…Bulk heterojunction polymer solar cells (BHJ PSCs) have received great attention due to their merits such as low‐cost, lightweight, flexibility, and roll‐to‐roll process. In the past two decades, tremendous efforts have been devoted to the development of novel materials, morphology control, and device optimization to attain improved power conversion efficiency (PCE) over 19% in single‐junction PSCs 1–9 . Despite rapid development, most of the high‐performance conjugated polymer for BHJ PSCs are processed with halogenated solvents such as chloroform (CF), chlorobenzene (CB), and 1,2‐dichlorobenzene (DCB), which can cause difficulties due to their toxicity, cost, and environmental concerns 10–13 …”

“…In the past two decades, tremendous efforts have been devoted to the development of novel materials, morphology control, and device optimization to attain improved power conversion efficiency (PCE) over 19% in single-junction PSCs. [1][2][3][4][5][6][7][8][9] Despite rapid development, most of the highperformance conjugated polymer for BHJ PSCs are processed with halogenated solvents such as chloroform (CF), chlorobenzene (CB), and 1,2-dichlorobenzene (DCB), which can cause difficulties due to their toxicity, cost, and environmental concerns. [10][11][12][13] Recently, conjugated copolymers based on 5-fluorobenzo[c] [1,2,5]thiadiazole (fBT) have attracted much attention because they have many advantages such as broad absorption ability, proper energy levels, high charge carrier, and excellent charge carrier mobility.…”

PyThinFilm: Automated Molecular Dynamics Simulation Protocols for the Generation of Thin Film Morphologies

“…Despite the number of applications of MD to the analysis thin film morphology reported in the literature, most studies to date have been limited to analysis of the bulk properties of individual components of thin films ,,− or specific structural properties such as interfacial organization. − Increasingly, however, kinetic effects and the role of different deposition processes have been examined. As the thickness of functional thin films used in OLED and OSC devices is frequently on the order of a few 10s of nm to a few 100 nm, the perpendicular dimensions of the thinner films used in these devices are on a scale presently accessible by atomic MD simulations. ,− Consequently, it is now possible to develop MD simulation protocols that explicitly include a substrate and model film growth by directly mimicking processes involved in vacuum deposition ,,,− or solution processing ,,− rather than solely considering the bulk properties of the material. For example, in 2011, Muccioli et al simulated the vacuum deposition of pentacene onto a fullerene substrate using MD.…”