Enhanced performance in inverted polymer solar cells with D-π-A-type molecular dye incorporated on ZnO buffer layer

Chang Eun Song, Ka Yeon Ryu, Seong Jin Hong, Chinna Bathula, Sang Kyu Lee, Won Suk Shin, Jong Cheol Lee, Si Kyung Choi, Joo Hyun Kim, Sang Jin Moon

Research output: Contribution to journalArticlepeer-review

32 Scopus citations

Abstract

We report the superior characteristics of a ZnO buffer layer covered with a phenothiazine-based, π-conjugated donor-acceptor (D-π-A)-type organic dye (called "d-ZnO"). The use of this system for the performance enhancement of inverted bulk heterojunction polymer solar cells (PSCs) with the configuration of indium tin oxide/d-ZnO/polymer:PC71BM/MoO 3/Ag (PC71BM=[6,6]-phenyl C71 butyric acid methyl ester) is investigated. The layer of organic dyes anchored on the ZnO surface through carboxylate bonding reduces the shunt path on bare ZnO surface and provides better interfacial contacts and energy level alignments between the ZnO layer and the photoactive layer. This phenomenon consequently leads to highly enhanced photovoltaic parameters (fill factor, open-circuit voltage, and short-circuit current density) and power conversion efficiencies (PCEs). Inverted solar cells containing the d-ZnO layer not only revealed about 34 % (PCE: 4.37 %) and 18 % (PCE: 7.11 %) improvement in the PCEs of the representative poly-3(hexylthiophene) (P3HT) and low-band-gap poly{[4,8-bis-(2-ethyl-hexyl-thiophene-5-yl)-benzo[1,2-b:4,5-b']dithiophene-2, 6-diyl]-alt-[2-(2'-ethylhexanoyl)-thieno[3,4-b]thiophen-4,6-diyl]} (PBDTTT-C-T) polymer systems, respectively, but also showed 2-4 times longer device lifetimes than their counterparts without the organic dye layer. These results demonstrate that this simple approach used in inverted PSCs with a metal oxide buffer layer could become a promising procedure to fabricate highly efficient and stable PSCs. It's a cover up! A new organic dye self-assembled on ZnO surface through carboxylate bonding has positive effects on the photovoltaic performance of inverted polymer solar cells (PSCs). This dye is based on a D-π-A system and can mediate forward charge transfers, reduce back charge recombination, passivate ZnO surface defects, and give good energy level alignments leading to largely enhanced efficiency and stability in inverted PSCs.

Original languageEnglish
Pages (from-to)1445-1454
Number of pages10
JournalChemSusChem
Volume6
Issue number8
DOIs
StatePublished - Aug 2013

Keywords

  • bulk heterojunction
  • electro-optical materials
  • photovoltaic devices
  • surface modification
  • zinc oxide

Fingerprint

Dive into the research topics of 'Enhanced performance in inverted polymer solar cells with D-π-A-type molecular dye incorporated on ZnO buffer layer'. Together they form a unique fingerprint.

Cite this