Open AccessThermally induced degradation of PBDTTT-CT:PCBM based polymer solar cells
Author(s) -
Shahidul Alam,
Alexey Gavrik,
Rico Meitzner,
Stephanie Hoeppener,
Vladimir Dyakonov,
Andreas Baumann,
Ulrich S. Schubert,
Harald Hoppe
Publication year - 2019
Publication title -
journal of physics. d, applied physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.857
H-Index - 198
eISSN - 1361-6463
pISSN - 0022-3727
DOI - 10.1088/1361-6463/ab3b73
Subject(s) - polymer solar cell , materials science , photoactive layer , polymer , active layer , chemical engineering , pedot:pss , degradation (telecommunications) , fullerene , organic solar cell , charge carrier , photovoltaic system , open circuit voltage , layer (electronics) , polymer chemistry , organic chemistry , chemistry , optoelectronics , nanotechnology , composite material , voltage , thin film transistor , telecommunications , ecology , physics , quantum mechanics , computer science , engineering , biology
Thermally induced degradation of photovoltaic performance in bulk-heterojunction (BHJ) polymer solar cells as a result of changes either in the active layer morphology or at interfaces during operation at elevated temperature is a common phenomenon. In this work, we have studied the thermal stability of a high performance polymer:fullerene BHJ PSCcomprising a conjugated polymer poly{[4,8-bis-(2-ethyl-hexyl-thiophene-5-yl)-benzo[1,2-b:4,5-b0]dithiophene-2,6-diyl]-alt-[2-(20-ethyl-hexanoyl)-thieno[3,4-b]thiophen-4,6-diyl]} (PBDTTT-CT) and a fullerene derivative [6,6]-phenyl-C 70 -butyric acid methyl ester photoactive layer within a conventional device architecture of glass/ITO/PEDOT:PSS/active layer/Mg/Al. By varying the temperature exposure conditions, the degradation path has been identified as an interfacial change in the device rather than a bulk effect. Furthermore, charge carrier dynamics studied by open circuit corrected charge carrier extraction has shown that post-annealed devices suffer from charge extraction due to the development of interfacial changes as compared to the non-treated devices in both pristine and with 1,8-Diiodooctane added scenarios.