Highly Efficient Organic Light-Emitting Diodes with a p-type Hole Injection Layer

• Main Authors: Feng-chang Chang, 張鋒璋
• Other Authors: Shui-hsiang Su
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/24792793331718505792

碩士 === 義守大學 === 電子工程學系碩士班 === 97 === This study elucidates the optoelectronic properties of high-efficiency p-doping layer organic light-emitting diodes(OLEDs) with Vanadium oxide (V2O5)-doped 4,4’,4’’–tris(3-methylphenylphenylamino) (m-MTDATA) as a p-doping hole injection layer (p-HIL). The device structure is ITO/V2O5-doped m-MTDATA(x%, 10 nm)/NPB(30 nm)/C545T-doped Alq3(0.3%, 30 nm)/Alq3(10 nm)/LiF(0.5 nm)/Al(120 nm). The driving voltage is reduced dramatically when V2O5 is doped. Devices with 10 % V2O5 doping in m-MTDATA shows the highest luminance luminous and luminous efficiencies of 42400 cd/m2 and 19.35 cd/A , respectively, at a voltage 10 V. The device efficiency and luminance the promotion attributes when the V2O5 best doping concentration, m-MTDATA reacted with V2O5 to produce exciton, and many Intrinsic Carrier were formed between ITO and the organic surface. Study for the p-doped hole injection layer, for thin-film photovoltaic and thin-film analysis of volume measurements, respectively, characteristics of device to explore the reasons for improving. The UV-Vis absorption spectrum of the V2O5-doped m-MTDATA film shows additional absorption peaks at around 500 nm and 1287 nm wavelengths, which indicates the formation of charge transfer complex. We also used electron spectroscopy (X-ray Photoelectron Spectroscopy) to analyze of V elements and C spectra of individual elements of the chemical shift phenomenon. The V2O5 doped m-MTDATA films show additional absorption peaks at 1498.6 cm−1, which are originated from the C=C stretching bands, probably indicates that the m-MTDATA molecule are full ionized by CT complexation. Finally, the used of atomic force microscopy to analyze the doping concentration in the different surface roughness of thin films and found that p-doped hole injection layer components designed to improve the optical and electrical properties of the important factors.