基于一种将具有电荷传输性的双极性主体材料与蓝、黄光客体材料共蒸的单层结构的同质结结构, 制备了色温可调的白光有机电致发光器件(OLED)。由于不存在激子阻挡层, 单层结构容易发生漏电流现象, 致使OLED器件具有较高的工作电压和较低的电流/功率效率。在空穴/电子传输层进行p/n型掺杂的同质结结构则大大改善了器件性能。研究表明: 该种器件结构获得了相对较低的起压5.6 V, 较高的电流效率2.64 cd/A和低效率滚降, 其色坐标则随着亮度的增加沿着普朗克轨迹变化, 产生类似于太阳光的发光特性。另外, 对主体材料和共蒸层的电荷载流子的传输特性和复合机制也进行了一系列分析研究。

Homojunction structure involved p/n-doped layers in the organic charge transport layers of organic light-emitting diodes (OLEDs) was developed to achieve chromaticity-tunable white OLEDs. This structure based on a single-layer structure which had a bipolar host material and co-dopant of complementary blue and yellow emitters. A relatively low turn-on voltage of 5.6 V, a high current efficiency of 2.64 cd/A and a low efficiency roll-off were achieved. Moreover, the Commission Internationale d’Eclairage coordinates varied from (0.41, 0.43) to (0.32, 0.35), which shifted almost along with the Planckian locus as the luminance increased. In addition, the charge carrier transport properties and recombination mechanisms were investigated and analyzed.