掺杂二氧化钛纳米管对有机电致发光性能的影响

Influence of doping with titania nanotubes on performance of polymer light-emitting diodes

在聚合物电致发光器件中,通过在不同功能层中掺杂二氧化钛纳米管来改善器件的性能.由于二氧化钛纳米管具有p型传导特性,可以显著增大空穴传输层中载流子的迁移率.由于二氧化钛纳米管在发光层中可以增大发光材料分子的刚性,从而减少无辐射跃迁.当把二氧化钛纳米管掺杂到空穴缓冲层中时,由于其与有机分子的强相互作用,一方面降低了空穴的传导性,同时也减少了界面淬灭发光的缺陷态的产生.

The performance of polymer light-emitting diodes was optimized by dispersing titania nanotubes into different functional layers. When titania nanotubes are doped into the hole-transport layer, the hole mobility of the device is greatly increased due to the good p-type conductibility of titania nanotubes. In the case of doping titania nanotubes into emitting layer, irradivative recombination was decreased since organic molecules wrapped on outer surface or entering into the nanotube make the chain conformation of polymer molecules more open. At last, the device efficiency of PLEDs was greatly improved by doping titania nanotubes into the hole buffer layer. This contributes to strong interaction between the titania nanotube and the polymer. This interaction reduces not only the hole conductibility but also the creation of defect states on interface region which can quench the luminescence.