An Easy Approach to Control β-Phase Formation in PFO Films for Optimized Emission Properties.

Qi Zhang,Lang Chi,Erdan Gu,Ruidong Xia,Gang Hai,Xiangchun Li,Wei Huang,Yueting Fang

doi:10.3390/molecules22020315

Abstract

We demonstrate a novel approach to control β-phase content generated in poly(9,9-dioctylfluorene) (PFO) films. A very small amount of paraffin oil was used as the additive to the PFO solution in toluene. The β-phase fraction in the spin-coated PFO films can be modified from 0% to 20% simply by changing the volume percentage of paraffin oil in the mixed solution. Organic light emitting diodes (OLEDs) and amplified spontaneous emission (ASE) study confirmed low β-phase fraction promise better OLEDs device, while high β-phase fraction benefits ASE performance.

Highlights

Conjugated polymers are an important class of semiconductors, due to their low-cost, easy-fabrication, environment-friendly, and flexibility features
The investigations detailed below indicate that a small fraction of β-phase percentage of paraffin oil in the mixture PFO solution, the β-phase content was content can improve color purity and device performance in Organic light emitting diodes (OLEDs), while a relatively precisely tailored between 0% and 20%
We demonstrate a simple approach to precisely control β-phase fraction in PFO film

Summary

Introduction

Conjugated polymers are an important class of semiconductors, due to their low-cost, easy-fabrication, environment-friendly, and flexibility features. Well controlled “β-phase” content in a glassy PFO film can facilitate the performance of optoelectronic devices: an organic light emitting diode (OLED) with higher luminance efficiency and better stability [18]. Molecules solvent (such2017, as 22, cyclohexane [14] or cyclopentanone [21]) or in good solvent but with a high ofboiling point (such as isodurene) [21]; introducing small amount of high-boiling-point additives The investigations detailed below indicate that a small fraction of β-phase percentage of paraffin oil (from 0 to 0.5 vol %) in the mixture PFO solution, the β-phase content was content (around 2%) can improve color purity and device performance in OLEDs, while a relatively precisely tailored between 0% and 20%. Lasers.we can control the fraction of “β-phase” conformation of the PFO films to fit the different application such as OLED or lasers

Results and Discussion

Materials and Methods

Conclusions