Photo-degradation in air of the active layer components in a thiophene-quinoxaline copolymer: fullerene solar cell
Artikel i vetenskaplig tidskrift, 2016

We have studied the photo-degradation in air of a blend of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-di yl] (TQ1), and how the photo-degradation affects the solar cell performance. Using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, changes to the electronic structure of TQ1 and PCBM caused by illumination in ambient air are investigated and compared between the pristine materials and the blend. The NEXAFS spectra show that the unoccupied molecular orbitals of TQ1 are not significantly changed by the exposure of pristine TQ1 to light in air, whereas those of PCBM are severely affected as a result of photo-induced degradation of PCBM. Furthermore, the photo-degradation of PCBM is accelerated by blending it with TQ1. While the NEXAFS spectrum of TQ1 remains unchanged upon illumination in air, its valence band spectrum shows that the occupied molecular orbitals are weakly affected. Yet, UV-Vis absorption spectra demonstrate photo-bleaching of TQ1, which is attenuated in the presence of PCBM in blend films. Illumination of the active layer of TQ1: PCBM solar cells prior to cathode deposition causes severe losses in electrical performance.

blends

technology

mechanisms

Chemistry

photochemical stability

efficiency

organic photovoltaic devices

degradation

polymer

tof-sims

Physics

pcbm

Författare

R. Hansson

Karlstads universitet

Camilla Lindqvist

Karlstads universitet

L. K. E. Ericsson

Karlstads universitet

A. Opitz

Humboldt-Universität zu Berlin

Ergang Wang

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

E. Moons

Karlstads universitet

Physical Chemistry Chemical Physics

1463-9076 (ISSN) 1463-9084 (eISSN)

Vol. 18 16 11132-11138

Ämneskategorier

Atom- och molekylfysik och optik

DOI

10.1039/c5cp07752d

Mer information

Senast uppdaterat

2018-05-23