Soft-chemistry Route to P-I-N Heterostructured Quantum Dot Electroluminescence Device: All Solution-Processed Polymer-In
- PDF / 357,998 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 94 Downloads / 152 Views
0959-M04-05
Soft-chemistry Route to P-I-N Heterostructured Quantum Dot Electroluminescence Device: All Solution-Processed Polymer-Inorganic Hybrid QD-EL Device Soon-Jae Kwon, Kyung-Sang Cho, Byoung-Lyong Choi, and Byung-Ki Kim Display Device & Materials Lab, Samsung Advanced Institute of Technology, Mt. 14-1, Nongse-Dong, Giheung-Gu, Yongin-Si, 446-712, Korea, Republic of
ABSTRACT p-i-n heterostructured quantum-dot electroluminescence (QD-EL) device has been fabricated by soft-chemical process, which shows a low turn-on voltage comparable to conventional OLEDs. To construct the multilayered device structure, p-type polymer semiconductor was deposited on the ITO glass by sequential process of coating and thermal curing, thereupon a few monolayers of QD was spin-coated. n-type metal-oxide film was deposited on top of the QD luminescence layer by sol-gel method, providing a facile and lowcost route for the electron transport layer (ETL). Prior to solution-processed ETL fabrication, a pre-treatment was performed in order to chemically-immobilize the QDs. As a cathodic electrode, relatively air-stable aluminum was deposited. The electronic band structure of the integrated device guarantees a low turn-on voltage, as was anticipated.
INTRODUCTION Conventional organic light emitting devices (OLEDs) have a fashion of sequential layers of small molecules or polymers [1]. In spite of advantages of the OLED, the constituent organic thin films react with harmful materials such as oxygen or moisture and as a result originally amorphous thin film may be recrystallized or oxidized, generating a dark spot with a loss of the luminescence function [2]. In order to prevent such material- or device-deterioration, tight encapsulation is inevitable. Furthermore, conventional OLED fabrication process needs highcost vacuum evaporation equipments as well as skillful technology, raising manufacturing cost. Since a color-tuning effect was known in the quantum dot(QD), extensive and intensive research efforts have been focused on the application of QD as a light-emitting material. When adopted to electroluminescence (EL) device, the quantum-size effect of QD simultaneously manifests a facile color-tuning, high color-purity, and low turn-on voltage, unprecedented by the conventional organic or inorganic substances. This unique phenomenon makes the QD very attractive for an electroluminescence device or next generation display. In this respect, there have been research activities on quantum dot electroluminescence (QD-EL) device. The recent and on-going QD-EL researches have been mostly focused on device structures very similar to conventional OLEDs, where the organic emission layer is substituted with QDs and consequently demerits of OLED still remain therein [3]. On the other hand, very recently all inorganic-based QD-EL device was reported, which requires special facility in spite of low efficiency [4]. Here we report soft-chemistry route to p-i-n heterostructured QD-EL device, which consists of sequential layers of polymer(p-type semicondu
Data Loading...
