Ubiquitous carrier harvesting in organic solar cells with embedded indium-tin-oxide nano-electrodes

Abstract

Bulk heterojunction in organic solar cells allows adequate interfaces for the dissociation of photo-generated excitons. However, the intermixed donor- and acceptor-like materials do not guarantee successful carrier transport and collections. In this work, we demonstrate ubiquitous carrier harvesting characteristics by using embedded indium-tin-oxide nano-electrodes (NEs) with a conformal electro-polymerized coating of a hole conducting layer. Compared to its planar electrode counterpart, this device exhibits internal quantum efficiency insensitive to the distribution of carrier generation, as determined by angle-resolved absorption spectroscopy and photocurrent characteristics. The ubiquitous carrier harvesting characteristics offer a viable solution to organic thin-film devices fabricated on flexible substrates or operated under diffused ambient light. (C) 2013 Elsevier B.V. All rights reserved.