Enhanced Photoluminescence Intensity of Quantum Dot Films With the Sandwich Column Array Structure by Uniform Electrical Induction

Quantum dots (QDs) are ideal color-conversion materials for display fields. Preparation of micro-nanostructures is a mainstream method for obtaining a high photoluminescence (PL) intensity. Electrical induction, a method of preparing micro-nanostructures, was introduced to obtain QD films with high PL performance by preparing a sandwich column array structure (SCAS). By changing the spacer thickness, a series of SCAS-QD films were fabricated, after optimizing the voltage. The SCAS-QD layers with a 25- $\mu \text{m}$ spacer obtained the maximum PL enhancement of green light intensity: up to 42.8%. The enhancement was caused by the microcavity trapping and light extraction effects. The former could increase the utilization factor of blue light and the latter could increase the emission probability of green light. This is a simple, high-efficient, and low-cost method for preparing QD films with high PL performance without increasing the QD concentration.