Charge-Transfer State Energy and Its Relationship with Open-Circuit Voltage in an Organic Photovoltaic Device

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

26 Scopus Citations
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Author(s)

  • Zhiqiang Guan
  • Qingdan Yang
  • Ming-Fai Lo
  • Tsz-Wai Ng

Detail(s)

Original languageEnglish
Pages (from-to)14059-14068
Journal / PublicationJournal of Physical Chemistry C
Volume120
Issue number26
Publication statusPublished - 7 Jul 2016

Abstract

Charge-transfer state (CTS) plays a very important role in organic photovoltaic (OPV) devices. Especially the relationship between open-circuit voltage (VOC) and CTS has been widely discussed. It is proposed that the CTS energy (ECT) directly determines the VOC value; however, the ECTs measured from different techniques often show considerable discrepancy. Here four methods are applied to probe the ECT values in five different bulk-heterojunction polymer:fullerene OPVs. It is found that linear relationships exist between different ECT's and VOC values. The detailed energetic meanings of the ECT values measured from different techniques are discussed, and the origin of their discrepancy is analyzed. Lastly, based on a proposed energy model, a relationship is summarized to estimate VOC loss by considering the energetic broadening of CTS, bimolecular recombination, and dielectric effect. The results provide a guideline to forecast the VOC and investigate its loss in OPV.

Citation Format(s)

Charge-Transfer State Energy and Its Relationship with Open-Circuit Voltage in an Organic Photovoltaic Device. / Guan, Zhiqiang; Li, Ho-Wa; Cheng, Yuanhang; Yang, Qingdan; Lo, Ming-Fai; Ng, Tsz-Wai; Tsang, Sai-Wing; Lee, Chun-Sing.

In: Journal of Physical Chemistry C, Vol. 120, No. 26, 07.07.2016, p. 14059-14068.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review