光电器件中有机半导体薄膜的光学和电学性质研究（英文）

Optical and Electrical Properties of Organic Semiconductor Thin Films for Optoelectronic Devices

采用真空热蒸发制备了AlQ,BAlQ和NPB有机半导体薄膜样品,探讨了薄膜的透射、吸收和光学性质.制备了有机薄膜样品的夹心结构器件,研究了其电流-电压特性.结果表明:有机薄膜的透明性能良好,AlQ和BAlQ具有几乎相同的直接光学能隙(4.46 eV),大于NPB的能隙值(3.11 eV). AlQ,BAlQ和NPB内部自由载流子浓度具有相同的数量级(1022m^(-3),但NPB具有最高的零电场迁移率(1.75×10^(-8)cm^2(V^(-1)·s^(-1))和电导率(1.45×10^(-10)S·cm^(-1)).

Organic semiconductor thin films of tris(8-hydroxy-quinoline)aluminum(AlQ),aluminum(Ⅲ)bis(2-methyl-8-quninolinato)-4-phenylphenolate(BAlQ),andα-naphthylphenylbiphenyl amine(NPB)were deposited by vacuum sublimation.The transmission,abosorption and the optical properties of the thin films were investigated.In addition,the thin film devices of sandwich structure were fabricated and the current-voltage characteristics were studied.The results showed that the organic thin films were highly transparent.AlQ and BAlQ demonstrated almost the same direct energy bandgap(4.46 eV),which was larger than that of NPB(3.11 eV).The internal free carrier density of AlQ,BAlQ and NPB were of the same order of magnitude(10^22 m^-3),whereas NPB exhibited the highest zero-field mobility(1.750x10^-8 cm^2·V^-1·s^-1)and electrical conductivity(1.450x10^-10 S·cm^-1).