Quantum dot light-emitting devices have emerged as an important technology for display applications. Their emission is a result of recombination between positive and negative charge carriers that are transported through the hole and electron conductive layers, respectively. The selection of electron or hole transport materials in these devices not only demands the alignment of energy levels between the layers but also balances the flow of electrons and holes toward the recombination sites. In this work, we examine a method for device optimization through control of the charge carrier kinetics. We employ impedance spectroscopy to examine the mobility of charge carriers through each of the layers. The derived mobility values provide a path to estimate the transition time of each charge carrier toward the emitting layer. We suggest that an optimal device structure can be obtained when the transition times of both charge carriers toward the active layer are similar. Finally, we examine our hypothesis by focusing on thickness optimization of the electron transport layer.

量子点发光器件已经成为显示应用的重要技术。它们的发射是分别通过空穴层和电子导电层传输的正负电荷载流子复合的结果。在这些装置中电子或空穴传输材料的选择不仅要求各层之间的能级对准，而且还平衡了电子和空穴向复合位点的流动。在这项工作中，我们研究了一种通过控制载流子动力学来优化器件的方法。我们采用阻抗光谱法检查通过每个层的电荷载流子的迁移率。导出的迁移率值提供了一条路径，用于估算每个电荷载流子向发射层的过渡时间。我们建议当两个电荷载流子向有源层的跃迁时间相似时，可以获得最佳的器件结构。最后，我们通过关注电子传输层的厚度优化来检验我们的假设。