Semiconductor-Based Far-UVC: Current Status and Future Applications

Far-ultraviolet-C (far-UVC, 200–235 nm) light has attracted significant attention for its strong germicidal efficacy and its potential to inactivate bacteria and viruses while posing reduced risks to human skin and eyes compared with conventional 254 nm UVC sources. As hospital-acquired infections continue to impose substantial health and economic burdens worldwide, far-UVC technologies offer a promising approach for continuous, in-situ disinfection in clinical and public environments. Compared with mercury-based lamps, semiconductor far-UVC light-emitting diodes (LEDs) provide key advantages, including compact size, wavelength tunability, instant on/off operation, and environmental sustainability. However, widespread adoption of far-UVC LEDs is hindered by low efficiency, severe carrier injection imbalance, and efficiency droop associated with high-Al-content AlGaN materials. Addressing these fundamental limitations is critical for realizing practical, high-performance far-UVC LED systems.The overarching aim of this Research Topic is to advance the fundamental understanding and practical performance of far-UVC semiconductor light sources for safe and effective disinfection applications. This work seeks to identify and address the key physical limitations that restrict efficiency, reliability, and scalability of far-UVC LEDs, particularly those arising from material quality, polarization effects, and carrier transport in wide-bandgap semiconductors. By integrating recent advances in device design, polarization engineering, and modeling tools, the goal is to define viable pathways toward higher-efficiency, mercury-free far-UVC emitters. Ultimately, this research aims to support the development of robust far-UVC technologies that can be widely deployed in healthcare and public environments to mitigate infection risks.This Research Topic focuses on advances in semiconductor-based far-UVC light sources and their enabling materials, device physics, and applications. Contributions are invited on, but not limited to, the following themes:• AlGaN and related wide-bandgap materials for direct far-UVC emission• Polarization engineering, carrier injection strategies, and efficiency enhancement in far-UVC LEDs• Second-harmonic (SHG) and nonlinear frequency-conversion approaches to far-UVC generation, including χ² nonlinear materials and device integration• Semiconductor and hybrid platforms for UV frequency doubling (e.g., AlN, GaN, β-Ga₂O₃, diamond, and integrated photonic structures)• Design and modeling of resonant cavities, waveguides, and phase-matching schemes for efficient deep-UV SHG• Comparative studies of direct-emission versus frequency-converted far-UVC sources• Reliability, scalability, and system-level considerations for practical far-UVC deployment Topic editors: Tinh Tran, Wei-Chih Lai, Tongbo Wei Source: https://www.frontiersin.org/research-topics/80827/semiconductor-based-far-uvc-current-status-and-future-applications