Low Threshold Voltage and Carrier Injection Properties of Inverted Organic Light-Emitting Diodes with [Ca24Al28O64]4+(4e-) Cathode and Cu2-xSe Anode

被引：51

作者：

Yanagi, Hiroshi ^{[1
]}

Kim, Ki-Beom ^{[1
]}

Koizumi, Ikue ^{[1
]}

Kikuchi, Maiko ^{[1
]}

Hiramatsu, Hidenori ^{[2
]}

Miyakawa, Masashi

Kamiya, Toshio ^{[1
,2
]}

Hirano, Masahiro ^{[2
]}

Hosono, Hideo ^{[1
,2
]}

机构：

[1] Tokyo Inst Technol, Mat & Struct Lab, Midori Ku, Yokohama, Kanagawa 2268503, Japan

[2] Tokyo Inst Technol, Japan Sci & Technol Agcy, Frontier Res Ctr, ERATO SORST,Midori Ku, Yokohama, Kanagawa 2268503, Japan

来源：

JOURNAL OF PHYSICAL CHEMISTRY C | 2009年 / 113卷 / 42期

关键词：

INDIUM-TIN-OXIDE; ENERGY-LEVEL ALIGNMENT; WORK FUNCTION; INTERFACES;

D O I：

10.1021/jp906386q

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Carrier injection properties including threshold voltage of inverted ion-emission organic light-emitting diodes (ITOLED) were improved by applying room temperature stable electride [Ca24Al28O64](4+)(4e(-)) (C12A7:e(-)), which has a low work function of similar to 2.4 eV, and a p-type degenerated semiconductor Cu2-xSe to bottom cathode and top anode buffer layers, respectively. The formation of a low-barrier electron injection contact between C12A7:e(-) and tris(8-hydroxyqunoline)aluminum (Alq(3)) is demonstrated by the current-voltage characteristics of electron-only devices, as well as by photoelectron spectroscopy. The threshold voltage of the ITOLED is reduced by changing the bottom cathode from Al to C12A7:e(-) from 9 to 7.6 V at 10 mA cm(-2). A 5 nm thick Cu2-xSe top anode buffer layer, deposited at room temperature, reduced the threshold voltage further to similar to 2 V. The, luminance efficiency of ITOLED with a Cu2-xSe buffer layer is nearly twice as large as that without the buffer layer. We emphasize that developing new electrode materials is an effective means to improve the performance of not only OLED but also other new optoelectronic devices.

引用

页码：18379 / 18384

页数：6

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