No Cover Image

Journal article 24 views 1 download

Tail state limited photocurrent collection of thick photoactive layers in organic solar cells / James, Durrant; Wing Chung, Tsoi

Nature Communications, Volume: 10, Issue: 1, Start page: 5159

Swansesa University Authors: James, Durrant, Wing Chung, Tsoi

Abstract

We analyse organic solar cells with four different photoactive blends exhibiting differing dependencies of short-circuit current upon photoactive layer thickness. These blends and devices are analysed by transient optoelectronic techniques of carrier kinetics and densities, air photoemission spectro...

Full description

Published in: Nature Communications
ISSN: 2041-1723
Published: Springer Science and Business Media LLC 2019
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa52866
Tags: Add Tag
No Tags, Be the first to tag this record!
Abstract: We analyse organic solar cells with four different photoactive blends exhibiting differing dependencies of short-circuit current upon photoactive layer thickness. These blends and devices are analysed by transient optoelectronic techniques of carrier kinetics and densities, air photoemission spectroscopy of material energetics, Kelvin probe measurements of work function, Mott-Schottky analyses of apparent doping density and by device modelling. We conclude that, for the device series studied, the photocurrent loss with thick active layers is primarily associated with the accumulation of photo-generated charge carriers in intra-bandgap tail states. This charge accumulation screens the device internal electrical field, preventing efficient charge collection. Purification of one studied donor polymer is observed to reduce tail state distribution and density and increase the maximal photoactive thickness for efficient operation. Our work suggests that selecting organic photoactive layers with a narrow distribution of tail states is a key requirement for the fabrication of efficient, high photocurrent, thick organic solar cells.
Issue: 1
Start Page: 5159