Electroluminescence Performance Optimization of Films Based on the Change of Macroscopic Structure and Microscopic Calculation

Alternating-current electroluminescent (ACEL) films have witnessed tremendous advances in photoelectric display and electric field sensing considering the advantages of flexibility and eco-friendliness. Exploring the relationship between electroluminescence intensity and film structure is the key to deeply understanding the electroluminescence principle and optimizing the performance of ACEL films, while the current research is inadequate. In this article, the electroluminescence characteristics of Cu-doped ZnS films are investigated under various voltage conditions and with different structures of films. The finite element method (FEM) and DFT+U method are introduced to discuss the effects of layer thickness and luminescence centers number on the electroluminescence intensity of ACEL films from a structural point of view and a microscopic particle aspect, respectively. In addition, the mechanism of dielectric layer conductivity to enhance the electroluminescence intensity of ACEL films is revealed. This work demonstrates the feasibility of applying ACEL films to wearable electric field sensors and lays a foundation for the fabrication of high-performance ACEL films in the future.