The damaging effects of the acidity in PEDOT:PSS on semiconductor device performance and solutions based on non-acidic alternatives

Abstract

<p>Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), PEDOT:PSS, has been widely used as an effective hole transporting material in many different organic semiconductor devices for well over a decade.</p>

Recent Progress and Challenges toward Highly Stable Nonfullerene Acceptor‐Based Organic Solar Cells

“…[ 237 ] It is further found that the interfacial chemical reaction is found to be more severe in OSCs with a conventional device structure of glass/ITO/PEDOT:PSS/active‐layer/ZnO/Ag than that with an inverted device structure of (glass/ITO/ZnO/active layer/MoO 3 /Ag) owing to the high sensitivity of the INCN moieties in the ITIC molecule to acidic environment as well as the acidic nature of PEDOT:PSS. [ 68 ][ 238 ] Such interfacial chemical reaction can be effectively mitigated through the use of alternative interlayer materials to PEDOT:PSS, development of neutral analogues and introduction of barrier layers. [ 238 ] These findings highlight that careful engineering of the whole device architecture, not only limited to the BHJ, is required for addressing the degradation mechanisms and achieving superior long‐term stability of NFA OSCs.…”

“…[ 68 ][ 238 ] Such interfacial chemical reaction can be effectively mitigated through the use of alternative interlayer materials to PEDOT:PSS, development of neutral analogues and introduction of barrier layers. [ 238 ] These findings highlight that careful engineering of the whole device architecture, not only limited to the BHJ, is required for addressing the degradation mechanisms and achieving superior long‐term stability of NFA OSCs.…”

Highly Efficient Inverted Polymer Solar Cells Using an Indium Gallium Zinc Oxide Interfacial Layer

“…The most conventional device structures consist of indium tin oxide (ITO) as transparent electrode/poly(3,4‐ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) as hole transport layer (HTL)/photoactive layer/electron transport layer (ETL)/(calcium [Ca] or barium [Ba]) metal electrode, but highly acidic PEDOT:PSS destroys the ITO layer and reduces the device stability. [ 7,8 ] Different approaches have been applied to overcome the problems associated with the conventional structure. Some researchers attempted to replace PEDOT:PSS with other p ‐type semiconductors.…”

Advances in Carbon-Based Microfiber Electrodes for Neural Interfacing

“…The electrochemical properties of electrode materials have also been found to change following repetitive stimulation (Kozai et al, 2015). Other factors that contribute to the longer term instability of electrode performance include electrode site corrosion, as in tungsten electrodes (Sankar et al, 2014), and electrode material degradation, as in poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) (Cameron and Skabara, 2020). One strategy to overcome the issue of the inflammatory tissue responses is to use thin polymeric materials, such as polyimide (Castagnola et al, 2013(Castagnola et al, , 2014, Parylene-C (Agorelius et al, 2015) and SU-8 (Xie et al, 2015;Luan et al, 2017;Liu, 2018;Zhao et al, 2019) as the substrate for flexible MEAs to match the soft nature of the brain and minimize perpetual machinal trauma and inflammation.…”

“…In this study, microelectrodes were also coated with anti-biofouling materials, improving chronic electrode performance. The instability of conductive polymers has been suggested as one limitation for conducting polymer modified CF electrodes in chronic applications (Mandal et al, 2015;Cameron and Skabara, 2020). Patel et al (2016) compared the stability of PEDOT:pTS and PEDOT:PSS coatings using accelerated soaking tests and measured the change of impedance over time.…”