利用空穴型聚合物材料ROPPV-12[聚(十二烷氧基-对苯乙炔)]与电子型有机小分子材料Alq3(八羟基喹啉铝)配合制备了有机薄膜异质结发光二极管。发现该异质结器件在ROPPV-12的厚度保持为70nm、Alq3的厚度为20nm时,器件的性能最优,且电致发光完全来自ROPPV-12;而当Alq3的厚度为32nm时,发光区域则跨越了ROPPV-12与Alq3,器件在较低驱动电压下来自ROPPV-12的光发射占主导地位,随着电压的升高,Alq3的光发射逐渐占据了主导地位。在相同电压下,前一器件的亮度、电流、发光效率都要远高于后一器件。分析了其发光机理。

Light-emitting diodes based on ROPPV-12/Alq3 heterojunction were fabricated, in which ROPPV-12 [poly(2, 5-Didodecyloxy-1, 4-Phenylenevinylene)] was a hole type semiconducting polymer, and 8-hydroxyquinoline aluminum (Alq3) was an electron type semiconducting low mass organic material. The emission spectrum of the device based on heterojunction ROPPV-12 (70 nm)/Alq3 (20 nm) is similar to that of POPPV-12′s single layer device. The emission spectrum of the device based on heterojunction ROPPV-12 (70 nm)/Alq3 (32 nm) is composed of two parts, one is originated from ROPPV-12, the other is from Alq3. The emission from ROPPV-12 is the main emission at low drive voltage. While with the increase of drive voltage, the emission from Alq3 becomes the main emission gradually. In other words, the electroluminescence of the later device is color voltage-dependent. The brightness, current and luminescent efficiency of the former device is much better than the later device. The emission mechanism is presented.