» Articles » PMID: 38869608

Enhancement of Light Efficiency of Deep-Ultraviolet Light-Emitting Diodes by Encapsulation with a 3D Photonic Crystal Reflecting Layer

Overview
Date 2024 Jun 13
PMID 38869608
Authors
Affiliations
Soon will be listed here.
Abstract

Recently, UVC LEDs, which emit deep ultraviolet light, have found extensive applications across various fields. This study demonstrates the design and implementation of thin films of three-dimensional photonic crystals (3D PhCs) as reflectors to enhance the light output power (LOP) of UVC LEDs. The 3D PhC reflectors were prepared using the self-assembly of silica nanospheres on a UVC LED lead frame substrate via the evaporation-induced method (side) and the gravitational sedimentation method (bottom), respectively. These PhCs with the (111) crystallographic plane were deposited on the side wall and bottom of the UVC LED lead frame, acting as functional materials to reflect UVC light. The LOP of UVC LEDs with 3D PhC reflectors at a driving current of 100 mA reached 19.6 mW. This represented a 30% enhancement compared to commercial UVC LEDs with Au-plated reflectors, due to the UVC light reflection by the photonic band gaps of 3D PhCs in the (111) crystallographic plane. Furthermore, after aging tests at 60 °C and 60% relative humidity for 1000 h, the relative LOP of UVC LEDs with 3D PhC reflectors decreased by 7%, which is better than that of commercial UVC LEDs. Thus, this study offers potential methods for enhancing the light output efficiency of commercial UVC light-emitting devices.

References
1.
T H Tran G, Koike M, Uchikoshi T, Fudouzi H . Rapid Growth of Colloidal Crystal Films from the Concentrated Aqueous Ethanol Suspension. Langmuir. 2020; 36(36):10683-10689. DOI: 10.1021/acs.langmuir.0c01048. View

2.
Kim M, Kim J, Kim S . Hyperreflective photonic crystals created by shearing colloidal dispersions at ultrahigh volume fraction. Microsyst Nanoeng. 2024; 10:21. PMC: 10827709. DOI: 10.1038/s41378-024-00651-2. View

3.
Lai C, Chang C, Wang M, Wu M . CCT- and CRI-tuning of white light-emitting diodes using three-dimensional non-close-packed colloidal photonic crystals with photonic stop-bands. Opt Express. 2013; 21 Suppl 4:A687-94. DOI: 10.1364/OE.21.00A687. View

4.
Chen K, Wang C, Ke Y, Kao Y, Chen H, Lin Y . Ultraviolet-C AlGaN Resonant-Cavity Light-Emitting Diodes with Thermal Stability Pipe-AlGaN-Distributed Bragg Reflectors. ACS Omega. 2023; 8(3):3478-3483. PMC: 9878540. DOI: 10.1021/acsomega.2c07496. View

5.
Kebbi Y, Muhammad A, SantAna A, do Prado-Silva L, Liu D, Ding T . Recent advances on the application of UV-LED technology for microbial inactivation: Progress and mechanism. Compr Rev Food Sci Food Saf. 2020; 19(6):3501-3527. DOI: 10.1111/1541-4337.12645. View