Improvement in Polymer Light-Emitting Diode Performance Using Polymer Heterojunction Structure Prepared by Evaporative Spray Deposition from Ultradilute Solution

Abstract

We successfully demonstrated a significant improvement in polymer light-emitting diode performance by employing a polymer bilayer structure prepared by evaporative spray deposition from ultradilute solution (ESDUS). The bilayer structure consisted of two -conjugated polymers, where the top layer was deposited from tetrahydrofuran (THF) solution by ESDUS onto the preceding bottom layer composed of the other THF-soluble polymer. The external quantum efficiency (EQE) of the bilayer device is improved markedly in comparison with that of a corresponding single-layer device prepared by conventional spin-coating. Moreover, the EQE of the bilayer device tends to be constant throughout a wide current region, whereas that of single-layer devices increases gradually with current density. These observations indicate that carriers are effectively blocked at the polymer/polymer interface of the bilayer device.

Photolithography versus lift off process for patterning of sputtered indium tin oxide for flexible displays

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Wavelength-Selectivity of Organic Photoconductive Devices by Solution Process

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Polymer Field Effect Transistors of Polyfluorene Prepared by Evaporative Spray Deposition using Ultradilute Solution

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