On the electrical degradation and green band formation in α- and β-phase poly(9,9-dioctyfluorene) polymer light-emitting diodes

被引：20

作者：

Arredondo, B. ^{[1
]}

Romero, B. ^{[1
]}

Gutierrez-Llorente, A. ^{[1
]}

Martinez, A. I. ^{[1
]}

Alvarez, A. L. ^{[1
]}

Quintana, X. ^{[2
]}

Oton, J. M. ^{[2
]}

机构：

[1] Univ Rey Juan Carlos, Dpto Tecnol Elect, Madrid 28933, Spain

[2] Univ Politecn Madrid, Dpto Tecnol Foton, E-28040 Madrid, Spain

来源：

SOLID-STATE ELECTRONICS | 2011年 / 61卷 / 01期

关键词：

Polymer light-emitting diodes; Polyfluorene; beta-Phase; Degradation; CHARGE-LIMITED CURRENTS; POLYFLUORENE; EMISSION; MORPHOLOGY; INJECTION; POLY(9,9-DI-N-OCTYLFLUORENE); OXIDATION; PROPERTY; ORIGIN;

D O I：

10.1016/j.sse.2011.02.004

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

In this work we report a detailed comparison of optical and electrical degradation between alpha- and beta-phase poly(9,9-dioctyfluorene) (PFO) based diodes. Analysis of the EL spectra along continuous operation time in alpha- and beta-PFO based diodes reveals that the unwanted green emission traditionally associated to fluorenone is more likely to occur in a-phase PFO. The relative spectral areas arising from excitonic and vibronic transitions as well as fluorenone defects have been quantified by means of Gaussian deconvolution along the operation time. The relative spectral area associated to the formation of the fluorenone increases 13% for the beta-PFO diode and up to 21% for the alpha-PFO diode only after 35 min of continuous operation. Analysis of the I-V curve before and after electrical stressing has lead to hole mobilities in pristine diodes of 1.4 x 10(-4) cm(2)/Vs and 1.6 x 10(-5) cm(2)/Vs for beta-PFO and alpha-PFO respectively. Both beta-PFO and alpha-PFO degraded samples show a reduction in the hole mobility, as well as an increase in the width of the Gaussian density of states. (C) 2011 Elsevier Ltd. All rights reserved.

引用

页码：46 / 52

页数：7

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