A new publication from Opto-Electronic Advances discusses rapid inactivation of human respiratory
The Need for Improved Disinfection Methods
Human respiratory RNA viruses, such as SARS-CoV-2 (the virus that causes Deep ultraviolet (DUV) light irradiation is an effective method for virus inactivation, as it damages viral genomes. Conventionally, mercury lamps are used for virus disinfection. However, these lamps suffer from various disadvantages, including toxicity, fragility, bulkiness, short lifetime, and ozone production. Moreover, the Minamata Convention on Mercury has prohibited the manufacture, import, and export of products containing mercury since 2020. Hence, there is an urgent need for an eco-friendly and efficient germicidal alternative.
AlGaN-based DUV LEDs as an Alternative
A DUV LED based on Aluminium Gallium Nitride (AlGaN), whose wavelength is tunable from 365 to 210 nm, presents a promising alternative to mercury lamps. This solution offers the benefits of being pollution-free, compact, and energy-conserving. Typically, these AlGaN-based DUV LEDs are heteroepitaxially grown on an Aluminium Nitride (AlN)/Sapphire template, as AlN single-crystal substrates are too costly. The Hydride Vapor Phase Epitaxy (HVPE) Thermal Annealing (HTA) method seems the most promising for obtaining a high-quality AlN/Sapphire template due to its simplicity, efficiency, and stability. However, it’s important to manage the strong compressive stress (SCS) exhibited by the HTA AlN/Sapphire template, which can affect the AlGaN quality and complicate the device fabrication process.
Research Methodology and Results
The authors of this article carried out research on the stress engineering, device preparation, and the inactivation efficiency of human respiratory RNA viruses using AlGaN-based DUV LEDs. The researchers discovered that by inserting a superlattice structure between the SCS AlN/sapphire substrate and the AlGaN epitaxial layer, the SCS could be effectively alleviated. This intervention reduced the dislocation density of the AlGaN epitaxial layer by over an order of magnitude and achieved an atomic-level flat surface, improving the quality of the epitaxial LED interface. The research team prepared AlGaN-based DUV LEDs with different peak wavelengths and studied their disinfection and sterilization effects on various human respiratory RNA viruses.
The study results showed that all the tested LEDs could achieve 100% disinfection and sterilization of SARS-CoV-2 and IAV within 60 seconds at a virus concentration of 3.8×10^5 PFU/mL. In particular, the 256 nm-LED demonstrated superior disinfection and sterilization efficiency, achieving 100% inactivation in just 10 seconds. Furthermore, this LED also performed excellently under higher virus concentrations and different virus attachment surface environments. These findings suggest that DUV LEDs could disinfect viruses more portably, environmentally-friendly, broadly, and efficiently.
Reference: “Rapid inactivation of human respiratory RNA viruses by deep ultraviolet irradiation from light-emitting diodes on a high-temperature-annealed AlN/Sapphire template” by Ke Jiang, Simeng Liang, Xiaojuan Sun, Jianwei Ben, Liang Qu, Shanli Zhang, Yang Chen, Yucheng Zheng, Ke Lan, Dabing Li and Ke Xu, 15 June 2023, Opto-Electronic Advances.
DOI: 10.29026/oea.2023.230004
The research group of Li Dabing and Sun Xiaojuan from the State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Precision Mechanics and Physics, Chinese Academy of Sciences, is mainly engaged in the research of wide band gap nitride semiconductor materials and their optoelectronic devices, involving materials and device physics, defect and doping control, structure epitaxy growth, LED and photodetector device preparation and application.
The research group has focused on the field of wide bandgap nitride