Optical and electrical properties of polymer light-emitting diodes with and without sulfide treatment

• Main Author: 游長峯
• Other Authors: 林祐仲
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/12460103424154824081

碩士 === 國立彰化師範大學 === 光電科技研究所 === 95 === In this study, the effects of the (NH4)2Sx treatment on the surface work function (SWF) of indium-tin-oxide (ITO) have been investigated. From the X-ray photoelectron spectroscopy and four point probe measurements, it is suggested that the surface chemical changes and an increase in the sheet resistance had strong influences on the SWF of ITO. After (NH4)2Sx treatment, a decrease in the number of oxygen vacancies near the ITO surface region could lead to an increase in the SWF of ITO. From the observed atomic force microscopy images and transmittance spectra, severe change following (NH4)2Sx surface treatment was not found. In addition, the comparison between the current- luminance-voltage characteristics of polymer light emitting diodes fabricated on ITO substrates with and without (NH4)2Sx treatment showed that (NH4)2Sx treatment led to the enhancement of external quantum efficiency due to the reduction of forward-biased leakage current and the increase in the recombination rate of electron-hole pairs.