Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2502.13551

Unusual Red Light Emission from Nonmetallic Cu$_2$Te Microdisk for Laser and SERS Applications

Qiuguo Li·Hao Rao·Xinzhou Ma·Haijuan Mei·Zhengting Zhao·Weiping Gong·Andrea Camposeo·Dario Pisignano·Xianguang Yang
View original source ↗Read source document ↗Export metadata ↓

Abstract

Physical characteristics of Cu$_2$Te are poorly investigated due to limited Te sources available and unclear atomic positions of crystal structure. Herein, hexagonal Cu$_2$Te microdisks are successfully prepared via chemical vapor deposition procedure using GaTe as Te source. The epitaxial growth mechanism of the Cu$_2$Te hexagonal structures with the orthorhombic phase are rationalized by proposed layer-over-layer growth model. The photoluminescence (PL) spectrum of Cu$_2$Te microdisks shows a new red emission band in addition to usual infrared light emission due to Cu deficiency. Single Cu$_2$Te microdisk operates as an optical microcavity supporting whispering gallery modes for red lasing around 627.5 nm. This Cu$_2$Te microdisk microcavity exhibits a high quality factor of 1568 and a low lasing threshold of 125 kW cm$^{-2}$ at room temperature. Meanwhile, Cu$_2$Te microdisks have been exhibited as an ideal platform for surface enhanced Raman scattering (SERS) eliminating drawbacks of noble metal substrates with detection limitation to nanomolar level and an enhancement factor of $\sim$1.95$\times$10$^5$. Hexagonal Cu$_2$Te microdisks turn out to be an efficient microcavity for red lasing and low-cost nonmetallic SERS substrates, opening potential applications in photonics and biological detection of aromatic molecules.

Explore related subjects

physics.app-phcond-mat.mtrl-sci

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Qiuguo Li, Hao Rao, Xinzhou Ma, Haijuan Mei, Zhengting Zhao, Weiping Gong, Andrea Camposeo, Dario Pisignano, Xianguang Yang. 2025-02-19. Unusual Red Light Emission from Nonmetallic Cu$_2$Te Microdisk for Laser and SERS Applications. https://doi.org/10.1002/adom.202101976

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Measuring vacancy-type defect density in monolayer semiconductors

Two-dimensional (2D) materials have attracted wide-spread interest due to their unique and tunable properties. Their optoelectronic, mechanical, and thermal properties are greatly influenced by crystal defects, which are, in turn, used to control these properties. However, experimental quantification of the density of defects, whether deliberately introduced or inherent, is very difficult in these atomically thin materials. Here we show that helium atom micro-diffraction can be used to measure the defect density in ~15x20um monolayer MoS2, a prototypical 2D semiconductor, quickly and easily compared to standard methods. We present a simple analytic model, the lattice gas equation, that captures the relationship between atomic Bragg diffraction intensity and defect density. The model, combined with ab initio scattering calculations, shows that our technique can immediately be applied to a wide range of 2D materials, independent of sample chemistry or structure. Additionally, wafer-scale characterization is immediately possible.

physics.app-ph↗
arXiv2026

Compact Modeling of Oxide-Semiconductor, 2D Material, Carbon Nanotube, and Cryogenic Transistors with Experiment Verification

This paper presents a unified compact model for emerging transistor technologies, including oxide-semiconductor field-effect transistors (OSFETs), 2D material FETs (2DFETs), carbon nanotube FETs (CNFETs), and cryogenic MOSFETs. A unified charge-density formulation is developed to account for quantum confinement, trap charges, and band-tail states in channel charge calculations. A physics-based transport model is introduced to seamlessly capture carrier transport from the long-channel diffusive regime to the short-channel ballistic limit. Scaling models are incorporated to accurately describe 2D electrostatic effects. Cryogenic operation is modeled through the inclusion of band-tail states and temperature-dependent mobility and threshold voltage. The proposed model is validated against experimental data from the fabricated OSFETs with multiple channel lengths and published measurements of 2DFETs, CNFETs, and cryogenic MOSFETs. Excellent agreement is demonstrated across diverse device architectures, operating conditions, and material systems.

physics.app-ph↗
arXiv2026

Multiplexing approaches to thermoradiative signatureless communications

Using mid-infrared emission from semiconductor devices for covert communications remains a relatively unexplored and yet promising opportunity. The phenomenon of negative luminescence allows for a method of signatureless covert communications where the net infrared emission of an emitting optoelectronic device is balanced to be identical to the ambient thermal background. In this work we provide a practical demonstration of covert data transfer over a thermoradiative channel with data rates up to 100 kbps. In addition, we demonstrate several additional multiplexing techniques that make the proposed thermoradiative communications method more secure against interception by achieving zero instantaneous optical emission, while remaining detectable if a sufficiently spatially or spectrally discerning observation is utilised. Finally, we discuss various application scenarios in which the proposed methods can be used to achieve secure signatureless communications.

physics.app-ph↗