Adsorption Behavior of NO and NO2 on Two-Dimensional As, Sb, and Bi Materials: First-Principles Insights.

To address the most significant environmental challenges, the quest for high-performance gas sensing materials is crucial. Among numerous two-dimensional materials, this study investigates the gas-sensitive capabilities of monolayer As, Sb, and Bi materials. To compare the gas detection abilities of these three materials, we employ first-principles calculations to comprehensively study the adsorption behavior of NO and NO2 gas molecules on the material surfaces. The results indicate that monolayer Bi material exhibits reasonable adsorption distances, substantial adsorption energies, and significant charge transfer for both NO and NO2 gases. Therefore, among the materials studied, it demonstrates the best gas detection capability. Furthermore, monolayer As and Sb materials exhibit remarkably high capacities for adsorbing NO and NO2 gas molecules, firmly interacting with the gas molecules. Gas adsorption induces changes in the material's work function, suggesting the potential application of these two materials as catalysts.

Cuproptosis Related Gene DLD Associated with Poor Prognosis and Malignant Biological Characteristics in Lung Adenocarcinoma.

PURPOSE: Cuproptosis plays a crucial role in the biological function of cells. The subject of this work was to analyze the effects of cuproptosis-related genes (CRGs) on the prognosis and biological function in lung adenocarcinoma (LUAD). METHODS: In this study, RNA sequencing and clinical data of LUAD samples were screened from public databases and our institution. A CRG signature was identified by least absolute shrinkage and selection operator and Cox regression. In addition, this study analyzed the correlation between prognostic CRGs and clinicopathological features. Finally, this study studied the effect of inhibiting dihydrolipoamide dehydrogenase (DLD) expression on cell biological function. RESULTS: There were 10 CRGs that showed differential expression between LUAD and normal tissues (p<0.05). A prognostic signature (DLD and lipoyltransferase 1 [LIPT1]) was constructed. Survival analysis suggested that patients with LUAD in the high-risk group had shorter overall survival (OS) (p<0.05). High expression of DLD and low expression of LIPT1 were significantly associated with shorter OS (p<0.05). Immunohistochemical analysis revealed that, in LUAD tissues, DLD was highly expressed, whereas LIPT1 was not detected. Finally, inhibition of DLD expression could significantly restrain cell proliferation, invasion and migration. CONCLUSION: Overall, this prognostic CRG signature may play a pivotal role in LUAD outcome, while oncogene DLD may be a future therapeutic candidate for LUAD.

The diagnosis and treatment for primary cardiac angiosarcoma with N-ras gene mutation and MSI-L: A case report and review of the literature.

RATIONALE: Primary cardiac angiosarcomas (PCA) is a rare malignancy with a poor prognosis. Currently, there is no standard treatment protocol for the PCA. We report a case of PCA in a 51-year-old woman. PATIENT CONCERNS: A 51-year-old woman initially presented with unexplained palpitations and chest tightness accompanied by nausea and vomiting, which worsened after activity and improved after rest. After symptomatic treatment, the symptoms improved, and the above symptoms recurred 8 months later. DIAGNOSES: Positron emission tomography-computed tomography revealed multiple lung nodules of varying sizes, some of which exhibited increased glucose metabolism. Furthermore, a soft tissue mass protruding into the pericardial cavity and involving the adjacent right atrium was observed in the right pericardium. The mass exhibited increased glucose metabolism, suggestive of a pericardial tumor with multiple lung metastases. Finally, histopathologic diagnosis of metastatic angiosarcoma was done by computed tomography-guided percutaneous lung and mediastinal biopsy. INTERVENTIONS: The patient was treated with palliative chemotherapy for the primary cardiac angiosarcomas and hematogenous lung metastasis. One cycle later, the result of Next-Generation Sequencing showed that the microsatellite instability status was determined to be low-level. Based on this result, tislelizumab was added to the original chemotherapy regimen. OUTCOMES: Unfortunately, the patient with PCA passed away after only 2 cycles of chemotherapy, and the cause of death remained unknown. LESSONS: This case report well demonstrates typical imaging findings of a rare cardiac angiosarcomas and emphasizes importance of early investigation for accurate diagnosis and proper management of the cardiac angiosarcomas.

Deletion of ARGLU1 causes global defects in alternative splicing in vivo and mouse cortical malformations primarily via apoptosis.

Haploinsufficient mutation in arginine and glutamine-rich protein 1 (Arglu1), a newly identified pre-mRNA splicing regulator, may be linked to neural developmental disorders associated with mental retardation and epilepsy in human patients, but the underlying causes remain elusive. Here we show that ablation of Arglu1 promotes radial glial cell (RG) detachment from the ventricular zone (VZ), leading to ectopic localized RGs in the mouse embryonic cortex. Although they remain proliferative, ectopic progenitors, as well as progenitors in the VZ, exhibit prolonged mitosis, p53 upregulation and cell apoptosis, leading to reduced neuron production, neuronal loss and microcephaly. RNA seq analysis reveals widespread changes in alternative splicing in the mutant mouse embryonic cortex, preferentially affecting genes involved in neuronal functions. Mdm2 and Mdm4 are found to be alternatively spliced at the exon 3 and exon 5 respectively, leading to absence of the p53-binding domain and nonsense-mediated mRNA decay (NMD) and thus relieve inhibition of p53. Removal of p53 largely rescues the microcephaly caused by deletion of Arglu1. Our findings provide mechanistic insights into cortical malformations of human patients with Arglu1 haploinsufficient mutation.

Defect recombination suppression and carrier extraction improvement for efficient CsPbBr3/SnO2heterojunction photodetectors.

Perovskite materials with excellent optical and electronic properties have huge potential in the research field of photodetectors. Constructing heterojunctions and promoting carrier transportation are significant for the development of perovskite-based optoelectronics devices with high performances. Herein, we demonstrated a CsPbBr3/SnO2heterojunction photodetector and improved the device performances through post-annealing treatment of SnO2film. The results indicated that the electrical properties of SnO2films will make an important impact on carrier extraction, especially for type-II heterojunction. As the electrons transfer layer in CsPbBr3/SnO2type-II heterojunction, defects related to oxygen vacancy should be the key factor to affect carrier concentration, induce carriers' limitation and recombination rate. Under proper annealing temperature for SnO2layer, the recombination rate can decrease to 1.37 × 1021cm3s and the spectral responsivity will be highly increased. This work can enhance the understanding on the photoresponse of perovskite photodetectors, and will be helpful for the further optimization and design of optoelectronic devices based on the perovskite heterojunction.

Band structural and absorption characteristics of antimonene/bismuthene monolayer heterojunction calculated by first-principles.

The band gap of lateral heterojunctions (LHSs) can be continuously tuned by changing the widths of their components. In this work, Sb/Bi LHSs based on monolayer Sb and Bi atoms with armchair and zigzag interfaces are constructed, respectively. It exhibits an atom's number in planner-dependent tunable band gap and near-infrared range absorption characteristics. They are systematically studied by first-principles calculations. The widths are represented by the number (n) of Sb or Bi atom chains. When n increases from 2 to 8, the bandgaps of armchair Sbn/Bin LHSs decrease from 0.89 to 0.67 eV, and the band gaps of zigzag Sbn/Bin LHSs decrease from 0.92 to 0.76 eV. The partial density of states spectra indicate that the occupied states of the valence band are mainly provided by the Bi 6p orbitals. Additionally, the unoccupied states of the conduction band are always provided by the Sb 5p orbitals and Bi 6p orbitals. For Sbn/Bin LHSs, the absorption edge along XX and YY directions move toward the long wavelength direction. These results provide an approach for the applications of two-dimensional materials in near-infrared devices.

Strain engineering of lateral heterostructures based on group-V enes (As, Sb, Bi) for infrared optoelectronic applications calculated by first principles.

In this work, the electronic structure, and optical properties of As/Sb and Sb/Bi lateral heterostructures (LHS) along armchair and zigzag interfaces affected by strain were investigated by density functional theory. The LHSs presented strain-dependent band transformation characteristics and sensitivity features. And a reduction and transition of the bandgap was observed when the As/Sb and Sb/Bi LHS existed under compressive strain. The density of states and the conduction band minimum-valence band maximum characteristics exhibited corresponding changes under the strain. Then a spatial charge-separation phenomenon and strong optical absorption properties in the mid-infrared range can also be observed from calculated results. Theoretical research into As/Sb and Sb/Bi LHSs has laid a solid foundation for As/Sb and Sb/Bi LHS device manufacture.

Review for Rare-Earth-Modified Perovskite Materials and Optoelectronic Applications.

In recent years, rare-earth metals with triply oxidized state, lanthanide ions (Ln3+), have been demonstrated as dopants, which can efficiently improve the optical and electronic properties of metal halide perovskite materials. On the one hand, doping Ln3+ ions can convert near-infrared/ultraviolet light into visible light through the process of up-/down-conversion and then the absorption efficiency of solar spectrum by perovskite solar cells can be significantly increased, leading to high device power conversion efficiency. On the other hand, multi-color light emissions and white light emissions originated from perovskite nanocrystals can be realized via inserting Ln3+ ions into the perovskite crystal lattice, which functioned as quantum cutting. In addition, doping or co-doping Ln3+ ions in perovskite films or devices can effectively facilitate perovskite film growth, tailor the energy band alignment and passivate the defect states, resulting in improved charge carrier transport efficiency or reduced nonradiative recombination. Finally, Ln3+ ions have also been used in the fields of photodetectors and luminescent solar concentrators. These indicate the huge potential of rare-earth metals in improving the perovskite optoelectronic device performances.

Self-Structural Healing of Encapsulated Perovskite Microcrystals for Improved Optical and Thermal Stability.

Perovskite materials and their optoelectronic devices have attracted intensive attentions in recent years. However, it is difficult to further improve the performance of perovskite devices due to the poor stability and the intrinsic deep level trap states (DLTS), which are caused by surface dangling bonds and grain boundaries. Herein, the CH3 NH3 PbBr3 perovskite microcrystal is encapsulated by a dense Al2 O3 layer to form a microenvironment. Through optical measurement, it is found that the structure of perovskite can be healed by itself even under high temperature and long-time laser illumination. The DLTS density decreases nearly an order of magnitude, which results in 4-14 times enhancement of light emission. The observation is ascribed to the micron-level environment, which serves as a self-sufficient high-vacuum growth chamber, where the components of the perovskite are completely retained when sublimated and the decomposed atoms can re-arrange after thermal treatment. The modified structure showing high thermal stability is able to maintain excellent optical and lasing stability up to 2 years. This discovery provides a new idea and perspective for improving the stability of perovskite and can be of practical interest for perovskite device application.

Photoresponse improvement of mixed-dimensional 1D-2D GaAs photodetectors by incorporating constructive interface states.

Mixed-dimensional optoelectronic devices bring new challenges and opportunities over the design of conventional low-dimensional devices. In this work, we develop unreported mixed-dimensional GaAs photodetectors by utilizing 1D GaAs nanowires (NWs) and 2D GaAs non-layered sheets (2DNLSs) as active device materials. The fabricated photodetector exhibits a responsivity of 677 A W-1 and a detectivity of 8.69 × 1012 cm Hz0.5 W-1 under 532 nm irradiation, which are already much better than those of state-of-the-art low-dimensional GaAs photodetectors. It is found that this unique device structure is capable of converting the notoriously harmful surface states of NWs and 2DNLSs into their constructive interface states, which contribute to the formation of quasi-type-II band structures and electron wells in the device channel for the substantial performance enhancement. More importantly, these interface states are demonstrated to be insensitive to ambient environments, indicating the superior stability of the device. All these results evidently illustrate a simple but effective way to utilize the surface states of nanomaterials to achieve the high-performance photodetectors.

Emission characteristics variation of GaAs0.92Sb0.08/Al0.3Ga0.7As strained multiple quantum wells caused by rapid thermal annealing.

Rapid thermal annealing is an effective way to improve the optical properties of semiconductor materials and devices. In this paper, the emission characteristics of GaAs0.92Sb0.08/Al0.3Ga0.7As multiple quantum wells, which investigated by temperature-dependent photoluminescence, are adjusted through strain and interfacial diffusion via rapid thermal annealing. The light-hole (LH) exciton emission and the heavy-hole (HH) exciton emission are observed at room temperature. After annealing, the LH and HH emission peaks have blue shift. It can be ascribed to the variation of interfacial strain at low annealing temperature and the interfacial diffusion between barrier layer and well layer at high annealing temperature. This work is of great significance for emission adjustment of strained multiple quantum wells.

Ultrafast carrier relaxation dynamics of photoexcited GaAs and GaAs/AlGaAs nanowire array.

Femtosecond optical pump-probe spectroscopy is employed to elucidate the ultrafast carrier nonradiative relaxation dynamics of bare GaAs and a core-shell GaAs/AlGaAs semiconductor nanowire array. Different from the single nanowire conventionally used for the study of ultrafast dynamics, a simple spin coating and peeling off method was performed to prepare transparent organic films containing a vertical oriented nanowire array for transient absorption measurement. The transient experiment provides the direct observation of carrier thermalization, carrier cooling, thermal dissipation and band-gap energy evolutions along with the carrier relaxations. Carrier thermalization occurs within sub-0.5 ps and proceeds almost independently on the AlGaAs-coating, while the time constants of carrier cooling and thermal dissipation are increased by an order of magnitude due to the AlGaAs-coating effect. The concomitant band-gap evolutions in GaAs and GaAs/AlGaAs include an initial rapid red-shift in thermalization period, followed by a slow blue and/or red shift in carrier cooling, and then by an even slower blue shift in thermal dissipation. The evolution is explained by the competition of band-gap renormalization, plasma screening and band-filling. These findings are significant for understanding the basic physics of carrier scattering, and also for the development of flexible optoelectronic devices.

Influence of the depletion region in GaAs/AlGaAs quantum well nanowire photodetector.

In semiconductor nanowire (NW) photodetectors, the Schottky barrier formed by the contact between metal and semiconductor can act as a depletion layer. For NW structures with a smaller diameter, the depletion region is especially important to the carrier transport. We prepared a GaAs/AlGaAs quantum well NW photodetector with a two-dimensional electron-hole tube, in which the two-dimensional hole tube (2DHT) formed by the inner layer of GaAs and AlGaAs has the most important role in the regulation of carriers. By adjusting the bias voltage to vary the depth of the depletion region, we have confirmed the influence of the depletion region in a 2DHT. A significant inflection point was found in the responsivity-voltage curve at 1.5 V. By combining the depletion region and 2DHT, the responsivity of the fabricated device was increased by 18 times to 0.199 A W-1 and the detectivity is increased by 5 times to 5.8 × 1010 Jones, compared to the pure GaAs NW photodetector. Reasonable combination of depletion layer and 2DHT was proved to promote high-performance NW photodetector.

Enhancing Performance of a GaAs/AlGaAs/GaAs Nanowire Photodetector Based on the Two-Dimensional Electron-Hole Tube Structure.

Here, we design and engineer an axially asymmetric GaAs/AlGaAs/GaAs (G/A/G) nanowire (NW) photodetector that operates efficiently at room temperature. Based on the I-type band structure, the device can realize a two-dimensional electron-hole tube (2DEHT) structure for the substantial performance enhancement. The 2DEHT is observed to form at the interface on both sides of GaAs/AlGaAs barriers, which constructs effective pathways for both electron and hole transport in reducing the photocarrier recombination and enhancing the device photocurrent. In particular, the G/A/G NW photodetector exhibits a responsivity of 0.57 A/W and a detectivity of 1.83 × 1010 Jones, which are about 7 times higher than those of the pure GaAs NW device. The recombination probability has also been significantly suppressed from 81.8% to 13.2% with the utilization of the 2DEHT structure. All of these can evidently demonstrate the importance of the appropriate band structure design to promote photocarrier generation, separation, and collection for high-performance optoelectronic devices.

Improved Optical Property and Lasing of ZnO Nanowires by Ar Plasma Treatment.

ZnO nanowires play a very important role in optoelectronic devices due to the wide bandgap and high exciton binding energy. However, for one-dimensional nanowire, due to the large surface to volume ratio, surface traps and surface adsorbed species acts as an alternate pathway for the de-excitation of carriers. Ar plasma treatment is a useful method to enhance the optical property of ZnO nanowires. It is necessary to study the optical properties of ZnO nanowires treated by plasma with different energies. Here, we used laser spectroscopy to investigate the plasma treatments with various energies on ZnO nanowires. Significantly improved emission has been observed for low and moderate Ar plasma treatments, which can be ascribed to the surface cleaning effects and increased neutral donor-bound excitons. It is worth mentioning that about 60-folds enhancements of the emission at room temperature can be achieved under 200 W Ar plasma treatment. When the plasma energy exceeds the threshold, high-ion beam energy will cause irreparable damage to the ZnO nanowires. Thanks to the enhanced optical performance, random lasing is observed under optical pumping at room temperature. And the stability has been improved dramatically. By using this simple method, the optical property and stability of ZnO nanowires can be effectively enhanced. These results will play an important role in the development of low dimensional ZnO-based optoelectronic devices.

Enhanced Photoresponsivity of a GaAs Nanowire Metal-Semiconductor-Metal Photodetector by Adjusting the Fermi Level.

Metal-semiconductor-metal (MSM)-structured GaAs-based nanowire photodetectors have been widely reported because they are promising as an alternative for high-performance devices. Owing to the Schottky built-in electric fields in the MSM structure photodetectors, enhancements in photoresponsivity can be realized. Thus, strengthening the built-in electric field is an efficacious way to make the detection capability better. In this study, we fabricate a single GaAs nanowire MSM photodetector with superior performance by doping-adjusting the Fermi level to strengthen the built-in electric field. An outstanding responsivity of 1175 A/W is obtained. This is two orders of magnitude better than the responsivity of the undoped sample. Scanning photocurrent mappings and simulations are performed to confirm that the enhancement in responsivity is because of the increase in the hole Schottky built-in electric field, which can separate and collect the photogenerated carriers more effectively. The eloquent evidence clearly proves that doping-adjusting the Fermi level has great potential applications in high-performance GaAs nanowire photodetectors and other functional photodetectors.

Optical characteristics of GaAs/GaAsSb/GaAs coaxial single quantum-well nanowires with different Sb components.

III-V ternary alloy quantum-wells have become a hot topic in recent years. Especially, GaAs/GaAsSb quantum wells have attracted increasing attention due to their numerous applications in the field of near-infrared optoelectronic devices. With the further reduction of dimensions, GaAs/GaAsSb nanowires show many special properties compared to their quantum well structures. In this work, GaAs/GaAs1-x Sb x /GaAs coaxial single quantum-well nanowires with different Sb composition were grown by molecular beam epitaxy. The band structure and the optical properties were investigated through power-dependent and temperature-dependent photoluminescence measurement. It has been found that a deeper quantum well is created with the increase of Sb component. Thanks to the deeper quantum well, more effective electron confinement has been realized, the emission from the sample can still be detected up to room temperature. The different trend of peak position and shape at various temperatures also supports the improved temperature stability of the samples. These results will be beneficial for the design of alloy quantum wells, and will facilitate the development of alloy quantum-well based devices.

Effect of Post Thermal Annealing on the Optical Properties of InP/ZnS Quantum Dot Films.

The enhancement of optical properties via thermal annealing on InP/ZnS core/shell quantum dot (QD) film was investigated in this work. The increase of emission intensities of the QD films was observed after thermal annealing at 180 °C for 5 min. Through temperature dependence photoluminescence (TDPL) and power dependence photoluminescence (PL) measurement, the peak located at the low-energy shoulder was confirmed to be localized state emission and the high energy one comes from free-carrier emission. Moreover, from the TDPL spectra of the sample annealed at 180 °C for 5 min, the full width at half maximum (FWHM) of localization state emission was nearly the same before which is 250 K and then decreased with increasing temperature. However, the FWHM was decreased significantly when temperature increased in the untreated sample. We conclude that the escape of localization states with increasing temperature contributes to this anomaly phenomenon. Our studies have significance on the application of QDs in electroluminescence devices and down-conversion light-emitting devices.

Analysis of the influence and mechanism of sulfur passivation on the dark current of a single GaAs nanowire photodetector.

Nanowire photodetectors, which have the advantages of fast response and high photoelectric conversion efficiency, can be widely applied in various industries. However, the rich surface states result in large dark current and can hinder the development of high-performance nanowire photodetectors. In this paper, the influence and mechanism of sulfur surface passivation on the dark current of a single GaAs nanowire photodetector have been studied. The dark current is significantly reduced by about 30 times after surface passivation. We confirm that the origin of the reduction of dark current is the decrease in the surface state density. As a result, a single GaAs nanowire photodetector with low dark current of 7.18 × 10-2 pA and high detectivity of 9.04 × 1012 cmHz0.5W-1 has been achieved. A simple and convenient way to realize high-performance GaAs-based photodetectors has been proposed.

Surface State Passivation and Optical Properties Investigation of GaSb via Nitrogen Plasma Treatment.

GaSb is one of the most suitable semiconductors for optoelectronic devices operating in the mid-infrared range. However, the existence of GaSb surface states has dramatically limited the performance of these devices. Herein, a controllable nitrogen passivation approach is proposed for GaSb. The surface states and optical properties of GaSb were found to depend on the N passivation conditions. Varying the plasma power during passivation modified the chemical bonds of the GaSb surface, which influenced the emission efficiency. X-ray photoelectron spectroscopy was used to quantitatively demonstrate that the GaSb oxide layer was removed via treatment at a plasma power of 100 W. After nitrogen passivation, the samples exhibited enhanced emission. Free exciton emission was the main factor leading to this enhanced luminescence. An energy band model for the surface states is used to explain the carrier radiative recombination processes. This nitrogen passivation approach can suppress surface states and improve the surface quality of GaSb-based materials and devices. The enhancement in exciton-related emission by this simple approach is important for improving the performance of GaSb-based optoelectronic devices.