Double-Sided Epitaxial Structure with Quantum Dots-Embedded Porous GaN for Enhanced Color Conversion

Abstract

Quantum dot enhancement films (QDEFs) have been widely used in mini-light-emitting-diode (mini-LED) backlight displays to meet the Rec. 2020 standard; however, these films consume excessive quantum dot (QD) materials and yield low light conversion efficiencies. Porous GaN has recently emerged as a promising alternative to the QDEFs approaches, owing to its ability to considerably enhance light conversion efficiency and reduce the consumption of QD materials. A novel double-sided epitaxial structure is proposed in which a blue LED epitaxial layer is grown on one side of a sapphire substrate, and a QD-embedded porous GaN layer is deposited on the opposite side. The proposed structure separates the porous layer from the LED epitaxial layer, unlike conventional monolithic porous GaN LED structures, thus enabling simultaneous optimization of light absorption and LED performance. The proposed structure with green and red QDs achieves light conversion efficiencies of 59% and 90%, respectively. The color gamut covers ≈122% of the National Television System Committee (1953) standard and 91% of the Rec. 2020 standard. These results suggest the potential of integrating QD-based color conversion layers into mini-LED backlight displays to develop next-generation display technologies. © 2025 Wiley-VCH GmbH.