arXiv subjects

Yaonan Hou

Publications and source records attributed to Yaonan Hou.

5 recordsLinked to original sources

arXiv2026

Roadmap on UV-C photodetectors: materials, applications and industry perspectives

UV-C photodetectors are poised to play an increasingly important role in future photonic technologies, driven by the rapid emergence of UV-C light sources and new wide bandgap semiconductors. These advances are enabling new levels of spectral selectivity, radiation hardness, sensitivity, and device integration, while opening opportunities across a broad range of applications. This roadmap provides a comprehensive overview of the current landscape of UV-C photodetection, spanning established and emerging material platforms (Ga2O3, AlGaN, BN, diamond, MgZnO, 2-dimensional materials, metal halide perovskites, micro-electromechanical systems), and their applications in metrology, astronomy, communications, environmental monitoring, fire detection, missile warning, gas sensing, and medical diagnostics. By identifying opportunities, bottlenecks, and future directions, this roadmap aims to support both newcomers and established researchers, with the aim of accelerating the translation of UV-C photodetectors into impactful technologies.

physics.app-ph↗

arXiv2026

A critical consideration of X-ray detectors based on Ga2O3: excitation, carrier transport mechanisms and performance standardization

X-ray detection underpins a wide range of applications in medicine, security, industrial inspection, scientific research for non-destructive imaging and material analysis. The rapid development of Ga2O3-based X-ray detectors offers a promising pathway toward next-generation detectors with high sensitivity, low noise, and harsh environment applications, benefiting from its intrinsic material properties such as high density, wide band gap energy, and high thermal-chemical stability. However, the underlying device operating mechanisms, including both carrier excitation and transport processes, have not yet been adequately studied, largely due to the misuse of X-ray sources in previous studies. Besides, benchmarking of device characteristics has been problematic due to experimental or data analysis issues, as well as misunderstandings of the applied equations associated with parameter definitions. In this work, we have designed and performed an instructive research work based on epitaxial beta-Ga2O3:Si and its planar Schottky detectors, measured with energy-tuneable monochromatic X-ray beams on a synchrotron beamline, clarifying the device excitation and carrier transport mechanisms with properly benchmarked device performance. In the end, we propose a set of protocols for correctly measuring and analysing the device performance. The proposed protocols are broadly applicable and can be readily extended to other semiconductor X-ray detectors.

physics.ins-det↗

arXiv2021

Supertoroidal light pulses: Propagating electromagnetic skyrmions in free space

Topological structures of electromagnetic fields could give access to nontrivial light-matter interactions and additional degrees of freedom for information and energy transfer. A characteristic example of such electromagnetic excitations are space-time non-separable single-cycle pulses, the exact solutions of Maxwell equation of toroidal topology predicted by Hellwarth and Nouchi in 1996 and recently observed experimentally. Here we introduce a new family of electromagnetic excitation of toroidal topology with increasing complexity in which the Hellwarth-Nouchi pulse is just the simplest member. The electromagnetic excitations of the new family can be parametrised by a single real number and exhibit skyrmionic structures of various orders. They feature multiple singularities in the electromagnetic and Poynting vector fields are accompanied by the fractal-like distributions of energy backflow. The generalized family of toroidal electromagnetic excitation with salient topologies are of interest for transient light-matter interactions, ultrafast optics, spectroscopy, and toroidal electrodynamics.

physics.optics↗

arXiv2017

GaZn-VZn acceptor complex defect in Ga-doped ZnO

Identification of complex defect has been a long-sought-after physics problem for controlling the defect population and engineering the useful properties in wide bandgap oxide semiconductors. Here we report a systematic study of (GaZn-VZn)- acceptor complex defect via zinc self-diffusion in Ga-doped ZnO isotopic heterostructures, which were conceived and prepared with delicately controlled growth conditions. The secondary ion mass spectrometry and temperature-dependent Hall-effect measurements reveal that a high density of controllable (GaZn-VZn)- is the predominant compensating defect in Ga-doped ZnO. The binding energy of this complex defect obtained from zinc self-diffusion experiments (~0.78 eV) well matches the electrical activation energy derived from the temperature-dependent electrical measurements (~0.82 eV). The compensation ratios were quantitatively calculated by energetic analysis and scattering process to further validate the compensation effect of (GaZn-VZn)- complex in Ga-doped ZnO. Meanwhile, its energy level structure was suggested based on the photoluminescence spectra, and the lifetime was achieved from the time-resolved photoluminescence measurements. The electron transitions between the (GaZn-VZn)- complex defect levels emit the light at ~650 nm with a lifetime of 10-20 nanoseconds. These findings may greatly pave the way towards novel complex defects-derived optical applications.

cond-mat.mtrl-sci↗

arXiv2016

Fluorine doping: A feasible solution to enhancing the conductivity of high-resistance wide bandgap Mg0.51Zn0.49O active components

N-type doping of high-resistance wide bandgap semiconductors, wurtzite high-Mg-content MgxZn1-xO for instance, has always been a fundamental application-motivated research issue. Herein, we report a solution to enhancing the conductivity of high-resistance Mg0.51Zn0.49O active components, which has been reliably achieved by fluorine doping via radio-frequency plasma assisted molecular beam epitaxial growth. Fluorine dopants were demonstrated to be effective donors in Mg0.51Zn0.49O single crystal film having a solar-blind 4.43 eV bandgap, with an average concentration of 1.0E19 F/cm3.The dramatically increased carrier concentration (2.85E17 cm-3 vs ~1014 cm-3) and decreased resistivity (129 ohm.cm vs ~10E6 ohm cm) indicate that the electrical properties of semi-insulating Mg0.51Zn0.49O film can be delicately regulated by F doping. Interestingly, two donor levels (17 meV and 74 meV) associated with F were revealed by temperature-dependent Hall measurements. A Schottky type metal-semiconductor-metal ultraviolet photodetector manifests a remarkably enhanced photocurrent, two orders of magnitude higher than that of the undoped counterpart. The responsivity is greatly enhanced from 0.34 mA/W to 52 mA/W under 10 V bias. The detectivity increases from 1.89E9 cm Hz1/2/W to 3.58eE10 cm Hz1/2/W under 10 V bias at room temperature.These results exhibit F doping serves as a promising pathway for improving the performance of high-Mg-content MgxZn1-xO-based devices.

cond-mat.mtrl-sci↗