利用有源层掺杂提高有机发光器件的电流效率

Improving Current Efficiency of Organic Light-Emitting Device by Using the Doping of Active Layer

通过对电子传输层和空穴传输层的共同掺杂 ,达到提高有机发光二极管 (OLED)电流效率的目的 .与常规的在电子传输层中掺杂有机染料的掺杂器件相比 ,本实验是在 Alq(电子传输层材料 )与 NPB(空穴传输层材料 )形成的均匀互掺有源层中 ,再掺杂染料 Rubrene.此种结构 ,其有源层能有效地限载流子而增加电子和空穴载流子相遇的几率 ,进而提高复合效率 ,使电流效率明显提高 .同时 ,有源层的连续生长避免了有机层间界面的形成 ,改善了器件的稳定性 .比较此结构器件与常规掺杂器件的特性 ,并对其发射机理进行讨论 .

By the joint doping of electron transport layer (ETL) and hole transport layer (HTL), the current efficiency of organic light emitting diode can be improved. As compared with conventional doped device with organic dye as dopant in ETL, Rubrene as dopant in the present experiment is doped into an active layer which is formed by uniformly mutual doping of Alq as material of ETL and NPB as material of HTL. The active layer in this structure will effectively confine the carriers and increase the probabilily of the meeting of electron carriers and hole carriers and then improve the efficiency of their combination and thus distinctly improve the current efficiency. Moreover, the continuous growth of active layer will prevent organic layers from forming an interface between them and will thus improve the stability of the device. The characteristics of this structure is compared with that of conventional doped device, and the mechanism of its light emission is discussed.