以CzHQZn为主体的有机发光器件的发光效率

采用真空热蒸镀技术,分别制备了结构为ITO/2T-NATA(25nm)/CzHQZn(10～25nm)/TPBi(35nm)/LiF(0.5nm)/Al、ITO/2T-NATA(30nm)/CBP:6%Ir(ppy)3:x%CzHQZn(20nm)/Alq3(50nm)/LiF(0.5nm)/Al和ITO/2T-NATA(30nm)/CBP:6%Ir(ppy)3:10%CzHQZn(xnm)/Alq3((70-x)nm)/LiF(0.5nm)/Al的3组有机电致发光器件(OLED)。器件中,CzHQZn既有空穴传输特性,又是黄光发射的主体。为了提高其发光效率,利用磷光敏化技术,研究了掺杂层中不同掺杂浓度和掺杂层不同厚度时器件的发光效率。结果表明,器件的效率随着掺杂发光层的厚度和掺杂浓度的变化而改变,当发光层的厚度为18nm时,CzHQZn掺杂浓度为10%的器件性能较好;在10V电压下,器件的最大电流效率达到3.26cd/A,色坐标为(0.4238,0.5064),最大亮度达到17560cd/m2。

Efficiency of an organic light-emitting devices based on CzHQZn as emitter

The organic light-emitting devices(OLEDs)using phosphorescent sensitizer have been fabricated by vacuum deposition technique.The device structures are ITO/2T-NATA(25 nm/CzHQZn(10～25 nm)/TPBi(35 nm)/LiF(0.5 nm)/Al,ITO/2T-NATA(30 nm)/CBP:6%Ir(ppy)3:x %CzHQZn(20 nm)/Alq3(50 nm)/LiF(0.5 nm)/Al,and ITO/2T-NATA(30 nm)/CBP:6%Ir(ppy)3:10 %CzHQZn(x nm)/Alq3((70-x)nm)/LiF(0.5 nm)/Al,respectively.The yellow-light emitting material CzHQZn has both strong hole-transporting and emitting properties.The efficiency of devices with different thicknesses of emitter and doping concentration of CzHQZn is studied.The results indicate that the efficiency of the devices changes with the thicknesses of emitter and the doping concentration of CzHQZn.When the emitting layer thickness is 18 nm and the doping concentration of CzHQZn is 10 wt%,a yellow-green OLED is obtained with Commission International de L’Eclairage coordinates of(0.42,0.51),the maximum luminous efficiency of 3.26 cd/A and the maximum luminance of 17 560 cd/m2 at applied voltage of 10 V.