UV- ozone treated graphene oxide/ PEDOT:PSS bilayer as a novel hole transport layer in highly efficient and stable organic solar cells
Document Type
Article
Publication Date
1-1-2019
Abstract
The utilization of UV-ozone (UVO) treated graphene oxide (GO)/PEDOT:PSS bilayer as hole transport layer (HTL) in solution processed organic solar cells (OSCs) is demonstrated. The HTLs were treated with UVO for 0, 5, 10 and 15 min. The 10 min treated OSC showed the best performance and displayed power conversion efficiency (PCE) of 5.24%, much higher than the untreated OSC device. This enhanced performance is mainly driven by improvements in the short circuit current (∼10.82 mA/cm2) as well as the fill factor (∼57%) that is ascribed to the moderate reduction of GO and increased work function (WF) of PEDOT:PSS after UVO treatment, which improved the contact conditions between the HTL and photoactive layer. Consequently, extraction efficiency of the photogenerated holes is increased, while recombination probability of holes and electrons in the photoactive layer is decreased. Moreover, the UVO-reduction of GO and consequently increased conductivity of reduced-GO (r-GO) has been modeled and proved using the density functional theory (DFT) simulation. Meanwhile, the 15 min UVO-treated OSC device showed severe reduction in the PCE that dropped to 2.11%, possibly due to various factors such as decomposition of chemical bonds, significant increase in the series resistance and pronounced drop in the photovoltaic performance parameters.
Keywords
UV-Ozone, Reduced graphene oxide, GO/PEDOT:PSS hole transport layer, DFT simulation of GO
Divisions
PHYSICS
Funders
High Impact Research (HIR) Grant UM.S/625/3/HIR/MoE/SC/26 with account number UM.0000080/HIR.C3 from the Ministry of Education, Malaysia,Postgraduate Research Grant PPP, University of Malaya, with Grant Number PG107- 2015B
Publication Title
Organic Electronics
Volume
66
Publisher
Elsevier