Efficiency enhancement of quantum dot–phosphor hybrid white-light-emitting diodes using a centrifugation-based quasi-horizontal separation structure

Abstract

In this paper, a centrifugation-based quasi-horizontal separation (c-HS) structure is proposed to enhance the QD light extraction of QD–phosphor hybrid white LEDs (WLEDs), effectively suppressing the backscattered loss from phosphor at the top region of the QD layer. Results indicate that a large centrifugation speed and dispensing mass of the QD layer is more beneficial to reducing the local density of phosphor at the top region, realizing quasi-horizontal separation between phosphor and QDs. Moreover, WLEDs with c-HS structure and conventional vertically layered packaging reference structure were compared at different correlated color temperatures (CCT). The radiant power and luminous flux achieved by the c-HS structure were 13.6% and 10.8%, respectively, higher than the reference structure at a typical warm white color of ∼4000 K. Consequently, this study can provide a new perspective on designing the separation structure for QD–phosphor hybrid WLEDs considering the backscattering loss of QD light.