Chen, W.-J.W.-J.ChenCheng, Y.-C.Y.-C.ChengKuo, D.-W.D.-W.KuoChen, C.-T.C.-T.ChenLiu, B.-T.B.-T.LiuJeng, R.-J.R.-J.JengLee, R.-H.R.-H.LeeRU-JONG JENG2020-03-022020-03-022018https://scholars.lib.ntu.edu.tw/handle/123456789/467515A novel triazole-cored, star-shaped, conjugated molecule (TDGTPA) has been synthesized for use as an electron-selective interlayer in inverted polymer solar cells (PSCs). This star-shaped molecule comprised a triazole unit as the central core, 2,5-thienyl diketopyrrolopyrrole units as π-conjugated bridges, and tert-butyl-substituted triphenylamine units as both end groups and donor units. The inverted PSC had the device structure indium tin oxide/ZnO/TDGTPA/poly(3-hexylthiophene) (P3HT)/fullerene derivative (PC71BM)/MoO3/Ag. Inserting TDGTPA as the electron-selective layer enhanced the compatibility of the ZnO-based electron transport layer and the P3HT:PC71BM blend-based photoactive layer. The low energy of the lowest unoccupied molecular orbital (-3.98 eV) of TDGTPA was favorable for electron transfer from the photoactive layer to the ZnO layer, thereby enhancing the photovoltaic performance of the PSC. The photo-conversion efficiency of the device incorporating TDGTPA as the electron-selective layer was 15.8% greater than that of the corresponding device prepared without it. © The Royal Society of Chemistry.[SDGs]SDG7Conjugated polymers; Electron transport properties; II-VI semiconductors; Indium compounds; Molecular orbitals; Molecules; Polymer solar cells; Stars; Synthesis (chemical); Tin oxides; Zinc oxide; Conjugated molecules; Diketopyrrolopyrroles; Electron transport layers; Inverted polymer solar cells; Lowest unoccupied molecular orbital; Photoactive layers; Photovoltaic performance; Star-shaped molecules; Solar cellsjournal article10.1039/c8ra05360j2-s2.0-85053545599https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053545599&doi=10.1039%2fc8ra05360j&partnerID=40&md5=8ef40fbda7f1e4ba7355aae6e98c1a00