Increasing the work function of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) by ultraviolet irradiation

Abstract

The effects of ultraviolet (UV) irradiation on the work function of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS) have been investigated in this study. Spectroscopic methods [x-ray photoelectron spectroscopy and Raman spectroscopy (532nm excitation)] and electrical conductivity measurements were used to characterize the electrical conducting polymer PEDOT:PSS prepared by UV irradiation. The authors found that UV irradiation could lead to an increase in the work function and the enhancement of electrical conductivity of PEDOT:PSS, resulting from a decrease in the number of the charge-trapping-related defects and the formation of linear or expanded-coil conformation.

Effective Approaches to Improve the Electrical Conductivity of PEDOT:PSS: A Review

“…function enhancement is critical to device performance. Lin et al [ 22 ] and Moujoud et al [ 7 ] found that UV irradiation could lead to an enhancement in conductivity and the work function of PEDOT:PSS. In order to study the mechanism of conductivity enhancement in PEDOT:PSS fi lms through UV-light treatment, Moujoud et al [ 7 ] employed X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) to investigate the electronic and structure changes in PEDOT:PSS fi lms.…”

Effects of ultraviolet treatment on the photovoltaic property of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate)/n-type Si diodes

“…This suggests negligible change in the trapped charges in the UV-treated PEDOT:PSS film. Based on the above result, we suggest that UV treatment may lead to a decreased number of charge-trapping-related defects, resulting in increased conductivity of PEDOT:PSS (that is, a reduction in R s ) [11,20]. On the other hand, the shape of the normalized C-V curve shown in Fig.…”

“…Ko et al [2] suggested that doping of PEDOT:PSS mainly affects R s only in the vertical direction. Recently, a method for enhancing the conductivity of PEDOT:PSS based on ultraviolet (UV) treatment was reported [11,12]. Benor et al [13] reported the use of UV-ozone exposure of PEDOT:PSS for improving the efficiency of OLEDs.…”

Maximizing the open-circuit voltage of polymer: Fullerene solar cells

“…Fortunately, the work function of PEDOT:PSS can be increased via treatment with UV-ozone or by mixing or covering with Nafion ® . [14][15][16][17][18] The changes in work function are reported to be 0.13 to 0.25 eV for UV-ozone treated films, [14][15][16] up to 0.65 eV for the films with Nafion ® . 17,18 Here we present poly͓3,6-di͑4Ј-ethyloctyl͒thieno ͓3,2-b͔ thiophene-2,5-diyl-2,1,3-benzothiadiazole-4,7-diyl͔ ͑PTTBT͒ ͑Fig.…”