The growing prevalence of counterfeit products worldwide poses serious threats to economic security and human health. Developing advanced anti-counterfeiting materials with physical unclonable functions offers an attractive defense strategy. Here, we report multimodal, dynamic and unclonable anti-counterfeiting labels based on diamond microparticles containing silicon-vacancy centers. These chaotic microparticles are heterogeneously grown on silicon substrate by chemical vapor deposition, facilitating low-cost scalable fabrication. The intrinsically unclonable functions are introduced by the randomized features of each particle. The highly stable signals of photoluminescence from silicon-vacancy centers and light scattering from diamond microparticles can enable high-capacity optical encoding. Moreover, time-dependent encoding is achieved by modulating photoluminescence signals of silicon-vacancy centers via air oxidation. Exploiting the robustness of diamond, the developed labels exhibit ultrahigh stability in extreme application scenarios, including harsh chemical environments, high temperature, mechanical abrasion, and ultraviolet irradiation. Hence, our proposed system can be practically applied immediately as anti-counterfeiting labels in diverse fields.

In this article, high-performance vertical gallium nitride (GaN)-on-GaN Schottky barrier diodes (SBDs) with helium (He)-implanted edge termination (ET) structure were demonstrated for the first time. Owing to the feature of He-implanted ET structure, the peak electric field crowding effect underneath the Schottky contact metal edge has been significantly reduced, thus increasing the breakdown voltage ${V}_{{\mathrm {BR}}}$ of the diodes. Under the same testing conditions, ${V}_{{\mathrm {BR}}}$ was increased from 862 to 1725 V for the devices with He-implanted ET structure, which also have low specific differential ON-resistance ${R}_{{\scriptscriptstyle {\mathrm {ON}}}}$ of 5.1 $\text{m}\Omega \cdot {\mathrm {cm}}^{2}$ and low turn-on voltage ${V}_{{\scriptscriptstyle {\mathrm {ON}}}}$ of 0.63 V. Given ${V}_{{\scriptscriptstyle {\mathrm {ON}}}}$ of < 0.7 V, the vertical GaN SBDs with He-implanted ET structure show the highest ${V}_{{\mathrm {BR}}}$ in the reported work up to today.

A normally- OFF AlGaN/GaN high-electron-mobility transistor (HEMT) with p-GaN gate was fabricated on free-standing GaN substrate. The self-terminated etching technology was achieved by combining with AlN stop layer and SF ₆ -based etching gas. Compared with HEMT on Si substrate (Si-HEMT), the HEMT on GaN substrate (GaN-HEMT) demonstrated the higher current density, lower subthreshold swing (SS), lower drain leakage current, and lower static and dynamic ON-resistance that were ascribed to the lower dislocation and less defect on free-standing GaN substrate. Meanwhile, the excellent ${V}_{\mathrm{th}}$ stability up to 175 °C and uniformity was demonstrated. Also, higher breakdown voltage (BV) of 683 V was measured, which was higher than 507 V for Si-HEMT. Hence, a normally- OFF AlGaN/GaN HEMT on free-standing GaN substrate shows good potential in power application.

In this study, red, green, cyan, warm white and cool white (RGCWW) LEDs are individually controlled to simulate dynamic daylight. The spectral power distributions (SPDs) are measured for both the daylight and the mixed white light. The correlated color temperature (CCT), circadian action factor (CAF) curves in the daytime of the mixed white LED almost overlap to those of daylight with a small error of about 1%. The CIE chromaticity coordinates of the mixed white light are distributed along the Planckian locus with a little deviation below 0.003. Also, its color rendering index (CRI) is above 90. The RGCWW five-chip LEDs of high circadian and visual performances will benefit to synchronize circadian rhythm in closed environment during long time without daylight, combined with better mood and alertness. The simulation errors and development trend of the mixed lighting are discussed.