同一种主体材料MADN中混掺不同的掺杂剂, 分别制备了两种白光有机发光二极管, 测试并研究了它们的发光效率、寿命、发光亮度、电致发光光谱以及色平衡度。结果表明, 两种白光器件的性能受发光层的顺序和厚度的影响显著。发光层顺序由阳极到阴极方向为橙/蓝的器件的稳定性要优于发光层顺序为蓝/橙的器件, 这是由于橙光发光层中的rubrene对空穴的陷进作用可捕获穿越橙光发光层中的空穴, 从而有效地调控了器件内部的电子、空穴浓度的平衡。通过对器件的优化, 制得了色坐标为(0.320 1, 0.345 9)的接近标准白光的有机电致发光器件。

Two types of white organic light-emitting devices (WOLED) containing a layered light-emitting region composed of a single blue-emitting host and different fluorescent dopants (blue and orange) were fabricated. The efficiency, lifetime, brightness, spectral voltage-dependence and white balance of devices were investigated. The results show that the performance of the devices strongly depends on the stack order of two emitting layers and the thickness of the emitting layer. It is found that the WOLED with an EML sequence of orange/blue (from anode to cathode) shows better stability than that with an EML sequence of blue/orange. It is due to the rubrene in orange emitting layer that acts as hole-trap sites and captures the passing holes and hence balances the concentration of electrons and holes. The optimized white device exhibits a favorable CIE coordinates (0.320 1, 0.345 9) which is close to the standard white light.