在量子点的研究中,对于量子点光致发光研究报道较多,而量子点电致发光研究报道较少,特别是对于混合量子点电致发光器件中能量转移机理的研究未见报道,由于不同量子点之间的能量转移机理决定着器件的性能,为此本论文对该方面进行了研究.分别制备了单种量子点器件和混合器件,混合器件是利用红、绿、蓝三种量子点按照1:1的比例两两混合,做成结构为ITO/PEDOT:PSS/QDs/Al的器件.研究发现在一定电压范围内,单种量子点器件的发光强度随着电压增加持续上升,而混合量子点器件的发光出现了短波长下降,长波长上升的现象,表明当有外加电场时不同尺寸的量子点间产生了较高效率的能量转移.同时首次对混合量子点电致发光器件能量转移的各项参数进行了计算,得到了能量转移效率E、临界能量转移距离R0与外加电场的关系,对制备混合量子点电致发光器件具有指导意义.
The hybrid quantum dot (QD) electroluminescent devices are fabricated by mixing every two kinds of QDs in the red, green, blue three types of QDs in a ratio 1:1, which are based on the structure of “ITO/PEDOT:PSS/QDs/Al”. In the systematical investigation of the electroluminescent spectrum, when the voltage increases, we find that the luminance intensity of the controlling devices continues to grow, while the hybrid QD devices first increase then decrease, showing that there is an energy transfer in the hybrid QD devices. And we also obtain the relationships among the energy transfer efficiency, the critical energy transfer distance, the donor-acceptor distance, and the electric field.