Document Type

Journal Article

Department/Unit

Department of Physics

Language

English

Abstract

The effect of zinc oxide (ZnO) electron extraction layer (EEL) on charge recombination and collection properties in bulk-heterojunction (BHJ) organic solar cells (OSCs), based on poly[[4,8-bis[(2-ethylhexyl)oxy] benzo [1,2-b:4,5-b'] dithiophene-2,6- diyl] [3-fluoro-2-[(2- ethylhexyl)carbonyl] thieno [3,4-b] thiophenediyl]] (PTB7):3'H-Cyclopropa[8,25] [5,6]fullerene-C70-D5h(6)-3'- butanoicacid, 3'-phenyl-, methyl ester (PC70BM) blend system, has been analyzed using the transient photo-current (TPC) and photo-induced charge extraction by linearly increasing voltage (photo-CELIV) measurements. The TPC and photo-CELIV results indicate that the trap-limited bimolecular recombination can be strongly suppressed by interposing a 20 nm thick ZnO EEL between the BHJ and cathode, leading to a 9.4% increase in power conversion efficiency. The presence of ZnO EEL is beneficial in efficient operation of OSCs in two ways: (1) suppressing trap-limited bimolecular recombination and (2) enhancing the charge collection at the organic/cathode interface.

Publication Date

2019

Source Publication Title

ACS Applied Energy Materials

Publisher

American Chemical Society

DOI

10.1021/acsaem.9b01383

Link to Publisher's Edition

https://doi.org/10.1021/acsaem.9b01383

ISSN (print)

25740962

Available for download on Tuesday, September 01, 2020

Included in

Physics Commons

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