Conductivity
and Stability Enhancement of PEDOT:PSS
Electrodes via Facile Doping of Sodium 3‑Methylsalicylate
for Highly Efficient Flexible Organic Light-Emitting Diodes
posted on 2021-12-30, 19:37authored byLihui Liu, Lei Wu, Hao Yang, Honggang Ge, Juxuan Xie, Kun Cao, Gang Cheng, Shufen Chen
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)
(PEDOT:PSS)
is one of the most prospering transparent conductive materials for
flexible optoelectronic devices, which arises from its nonpareil features
of low-cost solution processability, tunable conductivity, high transparency,
and superior mechanical flexibility. However, acidity and hygroscopicity
of PSS chains cause a decrease in conductivity, substrate corrosion,
and device degradation. This work proposes a facile and effective
direct doping strategy of sodium 3-methylsalicylate to enhance the
conductivity, alleviate the acidity, and improve the stability of
PEDOT:PSS electrodes, simultaneously. Owing to the formation of weaker
acid and PSS-Na, PSS chains are disentangled from the coiled PEDOT:PSS
complexes, leading to the phase separation of PEDOT:PSS and the formation
of fibril-like PEDOT domains. Eventually, the sodium 3-methylsalicylate-modified
PEDOT:PSS electrode is employed in flexible organic light-emitting
diodes with an outstanding external quantum efficiency of up to 25%.
The improved performance is attributed to the more matched work function
and the as-formed interfacial dipole. The sodium 3-methylsalicylate-modified
PEDOT:PSS electrode with high conductivity and transmittance, superior
stability in the air as well as good mechanical flexibility has the
potential to be the most promising transparent conductive material
for flexible optoelectronic device applications.