Highly Improved Efficiency of Deep-Blue Fluorescent Polymer Light-Emitting Device Based on a Novel Hole Interface Modifier with 1,3,5-Triazine Core

Improving the Performance of Blue Polymer Light-Emitting Diodes Using a Hole Injection Layer with a High Work Function and Nanotexture

For light-emitting polymers with a deep highest occupied molecular orbital energy level used for polymer light-emitting diodes (PLEDs), the hole injection barrier and hole transport of the anode buffer layer are of vital importance for optimizing electroluminescent performance. In this study, high-work-function hole injection layers with nanotextures were achieved by modifying poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) with a perfluorinated ionomer (PFI) and n-butyl alcohol and were used to achieve a single-layer device without a hole transport layer. With such an interlayer, the PLEDs based on PPF-SO25 exhibit remarkable current efficiency over 13.0 cd A^-1, which significantly outperform the devices with regular PEDOT:PSS. To our knowledge, this performance is among the best reported for single-layer blue PLEDs. The bias-dependent capacitance curves of these PLEDs suggest a nonuniform surface distribution of PFI. Our findings show that the PFI-modified PEDOT:PSS not only operates as a high-work-function hole injection layer to facilitate hole injection but also as a potential inner scattering medium for light extraction.

Highly Efficient Inverted Perovskite Solar Cells With Sulfonated Lignin Doped PEDOT as Hole Extract Layer

Sulfonated-acetone-formaldehyde (SAF) was grafted with alkali lignin (AL) to prepare grafted sulfonated-acetone-formaldehyde lignin (GSL). Considering the rich phenolic hydroxyl groups in GSL, we detected a hole mobility of 2.27 × 10(-6) cm(2) V(-1) s(-1) with GSL as a hole transport material by space-charge-limited current model. Compared with nonconjugated poly(styrene sulfonic acid), GSL was applied as p-type semiconductive dopant for PEDOT to prepare water-dispersed

PEDOT

GSL.

PEDOT

GSL shows enhanced conductivity compared with that of

PEDOT

PSS. Simultaneously, the enhanced open-circuit voltage, short-circuit current density, and fill factor are achieved using

PEDOT

GSL as a hole extract layer (HEL) in sandwich-structure inverted perovskite solar cells. The power conversion efficiency is increased to 14.94% compared with 12.6% of

PEDOT

PSS-based devices. Our results show that amorphous GSL is a good candidate as dopant of PEDOT, and we provide a novel prospective for the design of HEL based on lignin, a renewable biomass and phenol derivatives.