Manipulation of optical field distribution in ITO-free micro-cavity polymer tandem solar cells via the out-of-cell capping layer for high photovoltaic performance

Lijian Zuo, Chih Yu Chang, Chu Chen Chueh, Yunxiang Xu, Hongzheng Chen, Alex K.Y. Jen

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Series-connected tandem organic photovoltaic devices (SCTOPVs) have been shown to provide higher power conversion efficiencies (PCEs) than the single junction devices due to the improved light harvesting. To achieve the optimal device performance of SCTOPVs, balancing the photocurrents generated from the sub-cells is critical according to the Kirchhoff law. In this work, we demonstrate that the out-of-cell capping layer of an ITO-free microcavity SCTOPV plays an important role in manipulating the optical field distribution in the constituent sub-cells for achieving balanced photocurrents and optimal photovoltaic performance. Two mirror-like electrodes, a semi-transparent ultrathin Ag capped with a dielectric TeO2 layer and a thick Ag electrode were used to construct an ITO-free top-illuminated microcavity configuration, in which certain frequencies of solar irradiance can resonate between the reflective surfaces. As a result, a top-illuminated ITO-free SCTOPV with a comparable performance (7.4%) to the ITO-based counterpart (7.5%) was demonstrated despite the inferior transmittance of the ultra-thin Ag relative to ITO.

Original languageEnglish
Pages (from-to)961-968
Number of pages8
JournalJournal of Materials Chemistry A
Volume4
Issue number3
DOIs
Publication statusPublished - Jan 1 2016
Externally publishedYes

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ASJC Scopus subject areas

  • Chemistry(all)
  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)

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