电子传输层厚度对LiBq_4蓝色有机电致发光器件的影响

Effect of Thickness of Electron Transporting Layer on Blue Organic Electroluminescent Device Using LiBq_4 as an Active Layer

制备了以LiBq4 为发光层 ,结构为ITO/CuPc/TPD/LiBq4 /Alq3 /LiF/Al的器件。器件的电致发光 (EL)光谱与LiBq4 薄膜的光致发光 (PL)光谱相同 ,峰值波长均为 4 92nm。改变电子传输层Alq3 的厚度时 ,器件的电流 -电压特性及发光光谱随之发生变化 ,当电子传输层的厚度为 5nm时 ,既可以避免电子传输层的发光 ,又可以降低器件的工作电压。

Devices with the structure of ITO/CuPc/TPD/LiBq_4/Alq_3/LiF/Al,LiBq_4 used as an active layer,were prepared. Electroluminescence (EL) spectra of the devices are very similar to photoluminescence (PL) spectrum of the single deposited LiBq_4 film with peak wavelength at 492 nm.The current-voltage characteristics and the luminescence of the devices have the dependence on thickness of the electron transporting layer (ETL) Alq_3.We found that the operating voltage of the device may be reduced without emergence of luminescence of ETL as the thickness of the ETL equals 5 nm.