Tailored Highly Transparent Composite Hole‐Injection Layer Consisting of Pedot:PSS and SiO₂ Nanoparticles for Efficient Polymer Light‐Emitting Diodes

Abstract

Nanocomposite organic/inorganic com­pounds are used to fabricate thick, conductive and highly transparent layers, which are used as hole injection and transport layers in OLEDs. The composite layers consist of SiO2‐nanoparticles and the polymer PEDOT:PSS. The filling fraction of PEDOT:PSS in these thick layers is reduced to 3.9%. OLEDs comprising such composite layers show an increased outcoupling efficiency.

Nanostructuring OLEDs to increase efficiency

“…Alternatively, bottom-up approaches may be applied. As shown by Riedel et al (2011) and depicted in Fig. 8.15 nanoparticles may be blended into the organic layers.…”

“…A quasi periodic buckling structure integrated in an OLED for effi ciency enhancement is demonstrated by Koo et al (2010). Possible non-periodic nanostructures for coupling guided modes to leaky modes include the integration of scattering nanospheres into the organic layers (Riedel et al , 2011) and rough internal interfaces (Riedel et al , 2010c). In principle two-dimensional grating structures and non-periodic scattering structures couple more guided modes to leaky modes as they infl uence all propagation directions.…”

Simultaneously Enhancing Light Extraction and Device Stability of Organic Light‐Emitting Diodes using a Corrugated Polymer Nanosphere Templated PEDOT:PSS Layer

“…Particularly, the decrease in the transmittance below a wavelength of 500 nm was distinctive, which is a typical signature of the absorption spectra of pristine PEDOT:PSS fi lm. [ 12,48 ] In contrast, the transmittance of Sample 4 was improved to the almost same extent as that of the ITO fi lm. To provide a quantitative understanding of the enhanced optical transmittance of the PS NS-PEDOT:PSS fi lm, we measured and calculated the absorption coeffi cients of both the PEDOT:PSS and PS NS-PEDOT:PSS fi lms as functions of wavelength based on the measured absorbance profi le and the fi lm thickness (see Supporting Information Figure S2, Table S1).…”

“…[ 8 ] Therefore, the effi cient extraction of generated light is a critical requirement for achieving highlyeffi cient OLEDs. For this purpose, various strategies have been proposed, including modifying the substrate, [ 9,10 ] introducing a scattering layer, [11][12][13] an array of micro-lenses, [14][15][16] the use of low-index materials, [17][18][19] and the use of patterned structures. [20][21][22][23][24][25][26][27][28][29] Introducing patterned layers in OLEDs represents an efficient approach to facilitating light extraction by forming periodic, corrugated structures.…”

Current transport mechanism of heterojunction diodes based on the reduced graphene oxide-based polymer composite and n-type Si

“…Among many conductive polymers, the beneficial properties of poly (3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS), such as high transparency, high strength, and flexibility, and excellent thermal and mechanical stability, have attracted significant interest for application in hybrid organic/inorganic devices. [1][2][3][4][5] Here, we investigated the reduced graphene oxide (RGO) in PEDOT: PSS structure as hybrid Si-based diodes. The carbon-based nanoscale materials have been used for the formation of hybrid materials which are used mainly as active layers in devices.…”