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Indexed by:期刊论文

Date of Publication:2014-08-04

Journal:CHEMISTRY-A EUROPEAN JOURNAL

Included Journals:SCIE、EI、PubMed、Scopus

Volume:20

Issue:32

Page Number:10170-10178

ISSN No.:0947-6539

Key Words:cyclic voltammetry; dyes/pigments; electron-deficient compounds; electron transport; oligomers

Abstract:A new ladder-conjugated star-shaped oligomer electron-transporting material TetraPDI-PF, with four perylene diimide (PDI) branches and a fluorene core, was efficiently synthesized. The oligomer is highly soluble in dichlorobenzene with a solubility of 155 mg mL(-1), which is higher than those of PDI (35 mg mL(-1)) and PDI-Phen (70 mg mL(-1)). Demonstrated by thermogravimetric analysis (TGA), the oligomer exhibits excellent thermal stability with the decomposition temperature (T-d) of 291.2 degrees C, which is 65 degrees C higher than that of PDI. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed to investigate the electrochemical properties. Although the CV curves of TetraPDI-PF are successively scanned for 15 cycles, they still remain invariable reduction potentials. The oligomer also shows outstanding photostability, even better than PDI, which maintains 99% fluorescence intensity after irradiation for 10 min using maximum laser intensity. In the steady-state space-charge-limited current (SCLC) devices, TetraPDI-PF exhibits higher intrinsic electron mobility of 2.22 x 10(-5) cm(2)V(-1) s(-1), three orders of magnitude over that of PDI (3.52x10(-8) cm(2)V(-1) s(-1)). The bulk heterojunction (BHJ) organic solar cells (OSCs) using TetraPDI-PF as non-fullerene acceptors and P3HT as donors give optimum power conversion efficiency (PCE) of 0.64 %, which is 64 times that of the PDI:P3HT BHJ cells.