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Defect single-photon emitters (SPE) in gallium nitride (GaN) have garnered great attentions in recent years due to the advantages they offer, including the ability to operate at room temperature, narrow emission linewidths, and high brightness. Nevertheless, the precise nature of the single-photon emission mechanism remains uncertain due to the multitude of potential defects that can form in GaN. In this work, our systematical investigation with the ab initio calculation indicates that carbon and silicon, as common dopants in gallium nitride, can interact with intrinsic defects in GaN and form new high-speed defect single-photon sources. Our findings identify a ternary defect NGaVNCN that possesses a short lifetime of less than 1 ns and a small zero-photon line (ZPL) of 864 nm. In other words, this defect can serve as a high-speed single photon source in the short wavelength window for fiber communication. In sharp contrast, the Si-supported defect NGaVNSiN has a higher unoccupied defect energy level which enters the conduction band and is therefore unsuitable for single photon emission. A systematic investigation has been conducted into the potential defects, thermal stability, and single-photon emission properties. The relaxation calculation and self-consistent calculations employed the Perdew–Burke–Ernzerhof exchange-correlation functional and Heyd–Scuseria–Ernzerhof exchange-correlation functional, respectively. These findings indicate the potential for high-performance single-photon sources through carbon or silicon doping of GaN. [ABSTRACT FROM AUTHOR]

The Si- and InP-based APDs as the most important weak light semiconductor photodetectors to have achieved commercial success and are widely used in irradiation environments. Investigating the influencing mechanism of neutron irradiation on the above two types of APDs is of scientific and practical importance. In this paper, the dark current and gain characteristics of Si- and InP-based APDs around breakdown voltage were analyzed in detail before and after irradiation. The increase of dark current and the decrease of gain were observed for both the neutron irradiated Si- and InP-based APDs. Generation centers induced by neutrons are responsible for the increased dark current. The decrease of gain can be attributed to the increase of multiplied dark current and the change of electric field distribution in APD. The Si-based APD exhibits soft breakdown with the breakdown voltage reduced by ~8 V under the neutron fluence of 1.0 × 1012 cm−2, while the soft breakdown occurs along with a small change of breakdown voltage of ~1.5 V under the neutron fluence of 1.0 × 1013 cm−2 for InP-based APD. The difference in the change of breakdown voltage probably occurs because the Si-based APD uses p-doped Si as the multiplication layer, in which the neutron induced carrier removing effect cannot be ignored to keep the electric field distribution away from the optimal state. Therefore, using an intrinsic multiplication layer in APD is helpful to improve the neutron radiation resistance. The findings here are not only useful for the radiation hardened design of APD, but also deepen the understanding of irradiation mechanism. [ABSTRACT FROM AUTHOR]

Nano air channel transistors (NACTs) provide numerous advantages over traditional silicon devices, including faster switching speeds, higher operating frequencies, and enhanced radiation hardness attributable to the ballistic transport of electrons. In the development of field-emission-based integrated circuits, low-power consumption rectifying nano air channel diodes (NACDs) play a crucial role. However, achieving rectification characteristics in NACDs is challenging due to their structural and material symmetry. This paper proposes a vertical GaN NACD with a consistent nano air channel fabricated using IC-compatible processes. The GaN NACD exhibits an exceptionally low turn-on voltage of 0.3 V while delivering a high output current of 5.02 mA at 3 V. Notably, it demonstrates a high rectification ratio of up to 2.2 × 10 5 , attributing to significant work function disparities within the GaN-Au structure, coupled with the reduction of Au surface roughness to minimize reverse current. Furthermore, the junction-free structure and superior material properties of GaN enable the NACD to be suitable for use in radiation-rich environments. With its potential as a fundamental component of ultrafast and ultrahigh-frequency integrated circuits, this intriguing and cost-effective rectifying diode is anticipated to garner widespread interest within the electronics community., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

With the rapid expansion of the Internet of Things (IoT), ensuring the security of personal and group information has become increasingly crucial. However, conventional optical scattering physical unclonable function (OS-PUF) faces challenges due to its linear scattering behavior. In this article, we propose a non-linear OS-PUF (NOS-PUF) that integrates electro-optic materials. By leveraging random refractive index fluctuations generated by the NOS-PUF, we mitigate modeling attacks based on the OS-PUF and bolster the overall security of the authentication process. Moreover, we introduce a novel modeling attack methodology based on scattering invariant modes (SIMs) that poses a significant threat to conventional OS-PUF and NOS-PUF authentication systems. Through extensive simulations, we demonstrate that our NOS-PUF achieves a remarkably lower false accept rate for modeling attacks utilizing SIMs, surpassing the entropy limit imposed by the Gabor filtering algorithm by more than five orders of magnitude. These results highlight the heightened security and increased information entropy offered by the proposed NOS-PUF, making it particularly suitable for applications demanding robust and high-security authentication measures.

Solar selective absorbers are the core part for solar thermal technologies such as solar water heaters, concentrated solar power, solar thermoelectric generators and solar thermophotovoltaics. Colorful solar selective absorber can provide new freedom and flexibility beyond energy performance, which will lead to wider utilization of solar technologies. In this work, we present a monolithic integration of colored solar absorber array with different colors on a single substrate based on a multilayered structure of Cu/TiN(x)O(y)/TiO(2)/Si(3)N(4)/SiO(2). A colored solar absorber array with 16 color units is demonstrated experimentally by using combinatorial deposition technique via changing the thickness of SiO(2) layer. The solar absorptivity and thermal emissivity of all the color units is higher than 92% and lower than 5.5%, respectively. The colored solar selective absorber array can have colorful appearance and designable patterns while keeping high energy performance at the same time. It is a new candidate for a number of solar applications, especially for architecture integration and military camouflage.