Hole-Transport Layers Beyond PEDOT:PSS – Low-Temperature Solution-Processed MoOx derivatives Organic Solar Cell
Huei-Ting Chien
15:00 - 17:00 Thursday 23 October 2014 Rechbauerstrasse 12, HSII Organic photovoltaic solar cells (OPV) have received considerable attention around the world in recent years as a potential source of renewable energy. The advantages of OPV include easy fabrication, light weight, low manufacturing cost and potential mechanical flexibility.
The photoactive layer of OPV is commonly composed of a bulk –heterojunction-structure blend film of conjugated polymer donor and soluble fullerene derivative acceptor. Poly(3-hexylthiophene) (P3HT ) and phenyl-C61-butyric acid methyl ester (PCBM) are one of the most important donor and acceptor materials, respectively in the study of OPV.
By using a Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS ) as hole extraction layer, a interfacial buffer lies between indium tin oxide ( ITO ) and active polymer. It substantially improves stability and electrical performance of OPV owing to the reduction of the injection barrier against hole transfer from photoactive layer to the ITO anode.
Lately, molybdenum trioxide (MoO3) and its derivatives, receive growing attention used as hole extraction layer as replacement of PEDOT:PSS. PEDOT:PSS’s strong degradation due to the presence of moisture, is commonly made responsible for the short life time of the devices.
In this study, we demonstrate the use of two different solution processed molybdenum oxide derivatives (MoOx). One is a continuous film and the other is a discontinuous nanoparticle layer, incorporated as hole extraction layer in OPV. We show their impact on photo physics, OPV device physics, electronic properties and morphology in comparison with PEDOT:PSS and without hole extraction layer.
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