[Ba4 (S2 )][ZnGa4 S10 ]: Design of an Unprecedented Infrared Nonlinear Salt-Inclusion Chalcogenide with Disulfide-Bonds.

Salt-inclusion chalcogenides (SICs) have been receiving widespread attention due to their large second harmonic generation (SHG) responses and wide bandgaps, however most of them suffer from small birefringence limiting their technical application. Herein, by introducing the π-conjugated (S2 )2- units in the ionic guest of salt-inclusion structure, the first disulfide-bond-containing SIC, [Ba4 (S2 )][ZnGa4 S10 ] has been synthesized. It exhibits the widest bandgap up to 3.39 eV among polychalcogenides and strong SHG response as large as that of AgGaS2 (AGS). Importantly, its birefringence reaches a max value of 0.053@1064 nm among AGS-like SICs, indicating it is a promising IR nonlinear optical (NLO) material. Theoretical calculations reveal that the π-conjugated (S2 )2- units and covalent GaS layers favor the enhanced birefringence and large SHG response. This work provides not only a new type of SIC for the first time, but also new lights on the design of IR NLO materials.

In-line imaging and recognition of flip chip fabrication defects by real-time photoacoustic remote sensing system.

Microscopic defects in flip chips, originating from manufacturing, significantly affect performance and longevity. Post-fabrication sampling methods ensure product functionality but lack in-line defect monitoring to enhance chip yield and lifespan in real-time. This study introduces a photoacoustic remote sensing (PARS) system for in-line imaging and defect recognition during flip-chip fabrication. We first propose a real-time PARS imaging method based on continuous acquisition combined with parallel processing image reconstruction to achieve real-time imaging during the scanning of flip-chip samples, reducing reconstruction time from an average of approximately 1134 ms to 38 ms. Subsequently, we propose improved YOLOv7 with space-to-depth block (IYOLOv7-SPD), an enhanced deep learning defect recognition method, for accurate in-line recognition and localization of microscopic defects during the PARS real-time imaging process. The experimental results validate the viability of the proposed system for enhancing the lifespan and yield of flip-chip products in chip manufacturing facilities.

Bidirectional doping of two-dimensional thin-layer transition metal dichalcogenides using soft ammonia plasma.

Because of suitable band gap and high mobility, two-dimensional transition metal dichalcogenide (TMD) materials are promising in future microelectronic devices. However, controllable p-type and n-type doping of TMDs is still a challenge. Herein, we develop a soft plasma doping concept and demonstrate both n-type and p-type doping for TMDs including MoS2 and WS2 through adjusting the plasma working parameters. In particular, p-type doping of MoS2 can be realized when the radio frequency (RF) power is relatively small and the processing time is short: the off-state current increases from ∼10-10 A to ∼10-8 A, the threshold voltage is positively shifted from -26.2 V to 8.3 V, and the mobility increases from 7.05 cm2 V-1 s-1 to 16.52 cm2 V-1 s-1. Under a relatively large RF power and long processing time, n-type doping was realized for MoS2: the threshold voltage was negatively shifted from 6.8 V to -13.3 V and the mobility is reduced from 10.32 cm2 V-1 s-1 to 3.2 cm2 V-1 s-1. For the former, suitable plasma treatment can promote the substitution of N elements for S vacancies and lead to p-type doping, thus reducing the defect density and increasing the mobility value. For the latter, due to excessive plasma treatment, more S vacancies will be produced, leading to heavier n-type doping as well as a decrease in mobility. We confirm the results by systematically analyzing the optical, compositional, thickness and structural characteristics of the samples before and after such soft plasma treatments via Raman, photoluminescence (PL), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) measurements. Due to its nondestructive and expandable nature and compatibility with the current microelectronics industry, this potentially generic method may be used as a reliable technology for the development of diverse and functional TMD-based devices.

Genome-wide identification of cassava MeRboh genes and functional analysis in Arabidopsis.

Plant respiratory burst oxidase homolog (Rboh) gene family encodes NADPH oxidases, and plays important roles in the production of reactive oxygen species (ROS), plant signaling, growth and stress responses. Cassava is an important starchy crops in tropical region. Environmental stresses, such as drought, pathogen, have caused great yield loss. The mechanisms of stress response are little known in MeRBOH family of cassava. Investigation of Rboh genes response to disease may provide a clue for clarification the disease resistance mechanisms. In this study, eight MeRboh genes were identified from the cassava genome. Comparisons of gene structure, protein motifs, and a phylogenetic tree showed conservation of Rboh gene families in cassava, Arabidopsis and rice. Transcript levels of most MeRboh genes increased following treatment with a pathogen, Xanthomonas axonopodis pv. manihotis, or with phytohormones salicylic acid or jasmonic acid. Analysis of cis-acting elements also indicated that MeRboh genes could response to light, hormone, abiotic and biotic stress. Prediction of miRNA target and post-translation modification sites of MeRboh suggested possible regulations of miRNA and protein phosphorylation; and transient expression of MeRboh in cassava protoplasts confirmed their localization on plasma membrane. Expression of MeRbohB, MeRbohF partially complemented PAMP responses in Arabidopsis rboh mutants, including the expression of PTI marker FRK1, ROS production, peroxide accumulation and callose deposition. It suggesting that MeRbohB and MeRbohF may participate in the PTI pathway and contributed to ROS production triggered by pathogens. Moreover, overexpression of MeRbohB and MeRbohF enhanced the resistance of Arabidopsis against Pseudomonas syringae pv. tomato DC3000. Together, these results suggest the evolutionary conservation of MeRboh gene family and their important role in the immune response and in regulating the plant disease resistance, providing a foundation for revealing molecular mechanisms of cassava disease resistance.