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The limited oxidation stability of ether solvents has posed significant challenges for their applications in high‐voltage lithium metal batteries (LMBs). To tackle this issue, the prevailing strategy either adopts a high concentration of fluorinated salts or relies on highly fluorinated solvents, which will significantly increase the manufacturing cost and create severe environmental hazards. Herein, an alternative and sustainable salt engineering approach is proposed to enable the utilization of dilute electrolytes consisting of fluorine (F)‐free ethers in high‐voltage LMBs. The proposed 0.8 M electrolyte supports stable lithium plating‐stripping with a high Coulombic efficiency of 99.47 % and effectively mitigates the metal dissolution, phase transition, and gas release issues of the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode upon charging to high voltages. Consequently, the 4.5 V high‐loading Li||NCM 811 cell shows a capacity retention of 75.2 % after 300 cycles. Multimodal experimental characterizations coupled with theoretical investigations demonstrate that the boron‐containing salt plays a pivotal role in forming the passivation layers on both anode and cathode. The present simple and cost‐effective electrolyte design strategy offers a promising and alternative avenue for using commercially mature, environmentally benign, and low‐cost F‐free ethers in high‐voltage LMBs. [ABSTRACT FROM AUTHOR]

The limited oxidation stability of ether solvents has posed significant challenges for their applications in high‐voltage lithium metal batteries (LMBs). To tackle this issue, the prevailing strategy either adopts a high concentration of fluorinated salts or relies on highly fluorinated solvents, which will significantly increase the manufacturing cost and create severe environmental hazards. Herein, an alternative and sustainable salt engineering approach is proposed to enable the utilization of dilute electrolytes consisting of fluorine (F)‐free ethers in high‐voltage LMBs. The proposed 0.8 M electrolyte supports stable lithium plating‐stripping with a high Coulombic efficiency of 99.47 % and effectively mitigates the metal dissolution, phase transition, and gas release issues of the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode upon charging to high voltages. Consequently, the 4.5 V high‐loading Li||NCM 811 cell shows a capacity retention of 75.2 % after 300 cycles. Multimodal experimental characterizations coupled with theoretical investigations demonstrate that the boron‐containing salt plays a pivotal role in forming the passivation layers on both anode and cathode. The present simple and cost‐effective electrolyte design strategy offers a promising and alternative avenue for using commercially mature, environmentally benign, and low‐cost F‐free ethers in high‐voltage LMBs. [ABSTRACT FROM AUTHOR]

Colorectal cancer (COCA) has a poor prognosis, with growing evidence implicating basement membranes (BMs) in cancer progression. Our goal was to investigate the role and predictive significance of BMs in COCA patients. We obtained BMs‐related genes from cutting‐edge research and used TCGA and GTEx databases for mRNA expression and patient information. Cox regression and LASSO regression were used for prognostic gene selection and risk model construction. We compared prognosis using Kaplan–Meier analysis and examined drug sensitivity differences. The CMAP dataset identified potential small molecule drugs. In vitro tests involved suppressing a crucial gene to observe its impact on tumour metastasis. We developed a 12 BMs‐based approach, finding it to be an independent prognostic factor. Functional analysis showed BMs concentrated in cancer‐associated pathways, correlating with immune cell infiltration and immune checkpoint activation. High‐risk individuals exhibited increased drug sensitivity. AGRN levels were linked to decreased progression‐free survival (p < 0.001). AGRN knockdown suppressed tumour growth and metastasis. Our study offers new perspectives on BMs in COCA, concluding that AGRN is a dependable biomarker for patient survival and prognosis. [ABSTRACT FROM AUTHOR]

The causal relationship between lipid levels and bladder cancer is still inconclusive currently. We aimed to reveal the causal relationship between triglycerides, HDL, and LDL and the risk of bladder cancer by univariable and multivariable Mendelian randomization (MR) analysis. The single nucleotide polymorphisms (SNPs) of exposure (triglycerides: 441,016 samples; HDL: 403,943 samples; LDL: 440,546 samples) were obtained from UK Biobank. The Genetic variation related to bladder cancer included 1554 cases and 359,640 controls. Univariable and multivariable MR methods were conducted with subsequent analysis, and smoking was regarded as a confounder. The inverse-variance weighted (IVW), MR-Egger, weighted-median method, Cochran's Q test, and MR-PRESSO were considered the main MR analysis and sensitivity analysis methods. Univariable MR analysis results suggested the triglycerides level (P = 0.011, OR = 1.001, 95% CI = 1.000–1.002) was causally associated with increased risk of bladder cancer. Multivariable MR results indicated that higher triglyceride levels could still increase the risk of bladder cancer after adjusting the effects of HDL, LDL, and smoking (P = 0.042, OR = 1.001, 95% CI = 1.000–1.002). Our findings supported that triglyceride level is causally associated with an increased risk of bladder cancer independent of LDL and HDL at the genetic level. Timely attention to changes in blood lipid levels might reduce the risk of bladder cancer. [ABSTRACT FROM AUTHOR]

Background: With the increasing use of daratumumab (DARA)‐containing regimens for multiple myeloma (MM) patients in China, the standard infusion time of DARA is long, with the potential for infusion‐related reactions (IRRs) and increased hospitalization and use of resources. Shortening the duration of DARA infusion helps to optimize the hospital stay and enhance the patient treatment experience. The current, commonly used 90‐min rapid DARA infusion regimen may not be applicable to Chinese MM patients, and therefore, we explored a new 110‐min rapid DARA infusion regimen aimed at reducing the treatment burden on patients to guarantee therapeutic safety. Methods: MM inpatients treated with the DARA regimen were divided into two groups according to the number of times the DARA regimen was used: a standard infusion regimen for patients treated with the first two doses of DARA and a 110‐min rapid infusion regimen for patients treated with more than two doses of DARA. Anti‐allergy medications were routinely administered prior to the start of DARA infusion, patient consent, and authorization was obtained for all treatments, and statistical evaluation of the results was conducted via descriptive analyses, one‐way ANOVA and chi‐square tests. Results: A total of 129 patients were included in this study: 68 in the standard infusion group, with 121 DARA infusions, and 129 in the rapid infusion group (patients who participated in the standard infusion subsequently participated in the rapid infusion), with 738 DARA infusions. The incidence of IRRs was 27.27% (36/121) in the standard infusion group and 1.35% (10/738) in the rapid infusion group, which were significantly different (p < 0.001). The incidence of IRRs after rapid infusion in other studies was <6%. The incidence of grade 1 IRRs in the rapid infusion group was 0.81% (6/738), the incidence of grade 2 IRRs was 0.54% (4/738), and there were no IRRs above grade 3; age, sex, and underlying disease had no effect on the choice of infusion method (p > 0.05). The mean infusion time after the occurrence of IRRs was also shorter in the rapid infusion group than in the standard infusion group (F = 24.781, p < 0.001). Conclusion: The 110‐min rapid infusion DARA regimen is feasible and safe for use in Chinese MM patients. [ABSTRACT FROM AUTHOR]

Biomass‐derived hard carbon (HC) has emerged as a promising candidate for anode materials of potassium‐ion batteries because of low cost and abundant raw materials. Whereas, the large specific surface area and high porosity of this type of HC often lead to inferior initial Coulombic efficiency (ICE) and unsatisfactory cycling stability. Herein, we report a coconut shell‐derived HC (CS‐HC) featuring an expanded interlayer spacing and small specific surface area. The CS‐HC delivers a reversible specific capacity of 280 mAh g−1 and an impressive ICE of 87.32 % at 50 mA g−1. In addition, it exhibits stable cycling performance (92.8 % capacity retention after 100 cycles at 50 mA g−1) and fast rate capability (∼280 mAh g−1 at 300 mA g−1). The ex situ Raman spectra characterization combined with cyclic voltammetry tests elucidate that the storage of potassium ions in the present HC is mainly achieved by (pseudo)capacitive behavior at the disordered defect sites along with minor contribution from the interlayer intercalation process. Finally, a full‐cell constructed with unprecycled CS‐HC anode and high‐voltage K2Mn[Fe(CN)]6 cathode demonstrates exceptional electrochemical stability and retains 90.6 % capacity after 100 cycles. This work reports a high‐performance HC anode material derived from low‐cost and sustainable biomass for practical potassium‐ion batteries. [ABSTRACT FROM AUTHOR]

Purpose: Immune microenvironment plays an important role in aortic dissection (AD). Therefore, novel immune biomarkers may facilitate AD prevention, diagnosis, and treatment. This study aimed at mining key immune-related genes and relevant mechanisms involved in AD pathogenesis. Patients and Methods: Key immune cells in AD were identified by ssGESA algorithm. Next, genes associated with key immune cells were screened by weighted gene coexpression network analysis (WGCNA). Then hub immune genes were picked from protein-protein interaction network of overlapped genes from differential expression and WGCNA analyses by cytohubba plug-in. Their diagnostic potential was evaluated in two independent cohorts from GEO database. In addition, the expressions of hub immune genes were determined by quantitative RT-PCR, immunohistochemistry, and Western blotting in dissected and normal aortic tissues. Results: Activated B cells, CD56dim natural killer cells, eosinophils, gamma delta T cells, immature B cells, natural killer cells and type 17 T helper cells were identified as key immune cells in AD. Thereafter, a gene module significantly correlated with key immune cells were found by WGCNA method. Subsequently, KDR, IGF1, NOS3, PECAM1, GAPDH, FLT1, DLL4, CDH5, VWF, and TEK were identified as hub immune cell related genes by PPI network analysis, which may be potential diagnostic markers for AD, as evidenced by ROC curves. Moreover, the decreased expression of VWF in AD was validated at both mRNA and protein levels, and its expression was significantly positive correlated with the marker of smooth muscle cells, ACTA2, in AD. Further immunofluorescent results showed that VWF was colocalized with ACTA2 in aortic tissues. Conclusion: We identified key immune cells and hub immune cell-related genes involved in AD. Moreover, we found that VWF was co-expressed with the smooth muscle cell marker ACTA2, indicating the important role of VWF in smooth muscle cell loss in AD pathogenesis. [ABSTRACT FROM AUTHOR]

With the increasing demand for next‐generation electrochemical energy storage systems, various kinds of metal‐ion batteries have been developed in the past several decades, such as lithium‐ion batteries (LIBs), sodium‐ion batteries (NIBs), potassium‐ion batteries (KIBs), magnesium‐ion batteries (MIBs), zinc‐ion batteries (ZIBs), calcium‐ion batteries (CIBs), and aluminum‐ion batteries (AIBs). Due to its open structure, large interlayer spacings, multiple valence states, and reversible structural variations, layered V2O5, including two polymorphs of single layered α‐V2O5 and double layered V2O5 ⋅ nH2O, has been reported as a universal electrode material for all kinds of metal‐ion batteries mentioned above. In this review, we aim to summarize and compare the structure evolution of α‐V2O5 and V2O5 ⋅ nH2O during the insertion/extraction of various kinds of metal‐ions. This short review is expected to be helpful to comprehensively understand the structure evolution mechanism of α‐V2O5 and V2O5 ⋅ nH2O reacting with different metallic charge carriers and inspire the development of new electrode materials for high‐performance metal‐ion batteries. [ABSTRACT FROM AUTHOR]

Recently, to enhance the low-temperature performance of lithium-ion batteries (LIBs), significant efforts have been devoted to developing novel electrolytes with low viscosities, high conductivities, and facile Li-ion desolvation, while much less attention is paid to exploring optimum electrode materials for low-temperature LIBs. In this contribution, we discover that commercial microsized Cu2S exhibits a remarkably high performance toward lithium storage under ultra-low temperatures. Under room temperature, it delivers a reversible specific capacity of 318.8 mA h g−1 with very flat lithiation–delithiation plateaus around 1.75 V in Li metal cells. At −60 °C and a galvanostatic charge–discharge rate of 0.3C, it could still provide a reversible specific capacity of 168.8 mA h g−1 with stable cycling performance, promising its application in ultra-low-temperature Li-based batteries. Through a combination of microscopic, spectroscopic, and electrochemical characterization bolstered by theoretical calculations, the detailed reaction mechanisms and mechanistic understanding of the excellent low-temperature performances are proposed. This work points out the great opportunities to enhance the low-temperature performance of LIBs by discovering suitable electrode materials. [ABSTRACT FROM AUTHOR]

Adsorption is an important technology for the separation of different tea components. The adsorption behavior of L-theanine onto adsorbents was comprehensively studied in this paper. Among tested adsorbents, cation exchange resin ZGSPC106Na and D001SD were suitable for separating L-theanine, PVPP and PA-6 for catechins and macroporous resin HPD-400 for caffeine. Adsorption of L-theanine onto the cation resins was significantly influenced by the acidity, contact time and temperature. The adsorption behavior could be described by the pseudo-second-order rate equation and fitted to Langmuir and Freundlich models. ZGSPC106Na exhibited higher adsorption capacity, while D001SD showed higher adsorption selectivity. These might be attributed to the distinctive structure of the two resins and different ionization of the adsorbates. A method for simultaneous preparation of decaffeinated polyphenols, caffeine-enriched extract and decaffeinated L-theanine was established through successive separation on the columns fulfilled with PA-6, HPD-400 and D001SD, respectively. [ABSTRACT FROM AUTHOR]

The rechargeability of contemporary lithium‐ion batteries (LIBs) is challenging at low temperatures, mainly due to the hurdles faced by graphite anodes. Herein, by exploiting the Li‐solvent co‐intercalation into graphite, its low‐temperature rechargeability is boosted. Experimental characterizations aided by theoretical calculations demonstrate that the co‐intercalation process is featured by low interfacial resistance with a small charge transfer activation energy (0.23 eV atom−1) and an extremely low diffusion energy barrier (0.09 eV atom−1) which leads to nearly temperature‐independent diffusion coefficients of the solvated Li‐ion in graphite, enabling graphite to be stably charged‐discharged at −60 °C with 73.7 % of its room‐temperature capacity. Consequently, the full‐cell consisting of a LiNi0.65Co0.15Mn0.2O2 cathode and a graphite anode shows impressive rechargeability under −60 °C. This work provides an alternative approach to develop low‐temperature rechargeable LIBs. [ABSTRACT FROM AUTHOR]

The rechargeability of contemporary lithium‐ion batteries (LIBs) is challenging at low temperatures, mainly due to the hurdles faced by graphite anodes. Herein, by exploiting the Li‐solvent co‐intercalation into graphite, its low‐temperature rechargeability is boosted. Experimental characterizations aided by theoretical calculations demonstrate that the co‐intercalation process is featured by low interfacial resistance with a small charge transfer activation energy (0.23 eV atom−1) and an extremely low diffusion energy barrier (0.09 eV atom−1) which leads to nearly temperature‐independent diffusion coefficients of the solvated Li‐ion in graphite, enabling graphite to be stably charged‐discharged at −60 °C with 73.7 % of its room‐temperature capacity. Consequently, the full‐cell consisting of a LiNi0.65Co0.15Mn0.2O2 cathode and a graphite anode shows impressive rechargeability under −60 °C. This work provides an alternative approach to develop low‐temperature rechargeable LIBs. [ABSTRACT FROM AUTHOR]

The high activation barrier, inferior rate performance, and short cycling life severely constrain the practical applications of the high‐capacity Li2S cathode. Herein, we fabricate a Li2S−Cu nanocomposite with a drastically reduced activation potential, fast rate capability, and extraordinary cycling stability even under a practically relevant areal capacity of 2.96 mAh cm−2. Detailed experimental investigations aided by theoretical calculations indicate that instead of converting to S8 via troublesome soluble lithium polysulfides, Li2S is thermodynamically and kinetically more favorable to react with Cu by the displacement reaction, which alters the redox couple from Li2S/S to Cu/Cu2S, leading to the excellent electrochemical performance. Moreover, the stability of the composite is demonstrated in the full‐cell configuration consisting of commercial graphite anodes. This work provides an innovative and effective approach to realize highly activated and stable Li2S cathode materials. [ABSTRACT FROM AUTHOR]

The high activation barrier, inferior rate performance, and short cycling life severely constrain the practical applications of the high‐capacity Li2S cathode. Herein, we fabricate a Li2S−Cu nanocomposite with a drastically reduced activation potential, fast rate capability, and extraordinary cycling stability even under a practically relevant areal capacity of 2.96 mAh cm−2. Detailed experimental investigations aided by theoretical calculations indicate that instead of converting to S8 via troublesome soluble lithium polysulfides, Li2S is thermodynamically and kinetically more favorable to react with Cu by the displacement reaction, which alters the redox couple from Li2S/S to Cu/Cu2S, leading to the excellent electrochemical performance. Moreover, the stability of the composite is demonstrated in the full‐cell configuration consisting of commercial graphite anodes. This work provides an innovative and effective approach to realize highly activated and stable Li2S cathode materials. [ABSTRACT FROM AUTHOR]

In-plane anisotropic two-dimensional (2D) materials possess unique in-plane anisotropic physical properties arising from their low crystal lattice symmetry. Among these low-symmetry 2D materials, anisotropic Ge-based binary materials have the advantages of simple binary and earth-abundant compositions, good stability, highly anisotropic physical properties along two principle axes, and wide coverage of bandgaps, enabling use in broadband photodetection from the infrared to ultraviolet region. Here, we review recent progress in in-plane anisotropic 2D Ge-based binary materials, focusing on their anisotropic structural, electrical and optical properties. We then discuss demonstrations of optoelectronic applications related to those anisotropic properties including polarization-sensitive photodetection and polarization-based all-optical switches. Finally, we provide further possible opportunities for this relatively new, but quickly expanding family of materials. [ABSTRACT FROM AUTHOR]

Summary of main observation and conclusion: Colloidal quantum dots (CQDs) are attractive absorber materials for high‐efficiency photovoltaics because of their facile solution processing, bandgap tunability due to quantum confinement effect, and multi‐exciton generation. To date, all published performance records for PbS CQDs solar cells have been based on the conventional hot‐injection synthesis method. This method usually requires relatively strict conditions such as high temperature and the utility of expensive source material (pyrophoric bis(trimethylsilyl) sulfide (TMS‐S)), limiting the potential for large‐scale and low‐cost synthesis of PbS CQDs. Here we report a facile room‐temperature synthetic method to produce high‐quality PbS CQDs through inexpensive ionic source materials including Pb(NO3)2 and Na2S in the presence of triethanolamine (TEA) as the stabilizing ligand. The PbS CQDs were successfully prepared with an average particle size of about 5 nm. Solar cells based on the as‐synthesized PbS CQDs show a preliminary power conversion efficiency of 1.82%. This room‐temperature and low‐cost synthesis of PbS CQDs will further benefit the development of solution‐processed CQD solar cells. [ABSTRACT FROM AUTHOR]

As a representative in-plane anisotropic two-dimensional (2D) material, germanium monoselenide (GeSe) has attracted considerable attention recently due to its various in-plane anisotropic material properties originating from the low symmetry of a puckered honeycomb structure. Although there have been plenty of reports on the in-plane anisotropic vibrational, electrical and optical properties of GeSe, the strain effect on those appealing anisotropies is still under exploration. Here we report a systematic first-principles computational investigation of strain-engineering of the anisotropic electronic properties of GeSe monolayers. We found that the anisotropic ratio of the effective mass and mobility of charge carriers (electrons and holes) of GeSe along two principle axes can be controlled by using simple strain conditions. Notably, the preferred conducting direction of GeSe can be even rotated by 90° under an appropriate uniaxial strain (>5%). Such effective strain modulation of the electronic anisotropy of GeSe monolayers provides them abundant opportunities for future mechanical-electronic devices. [ABSTRACT FROM AUTHOR]

When tested as the cathode material for potassium-ion batteries, K2V3O8 delivers a highly reversible capacity of over 100 mA h g−1 in the voltage range of 1.5–4.5 V with 73% capacity retained after 50 cycles. Charge–discharge is achieved by a nontopotactic process between K2V3O8 and KV3O8 (ΔV ∼ −23.4%), causing the slow capacity decay. [ABSTRACT FROM AUTHOR]

Pseudogenes play a crucial role in cancer progression. However, the role of pituitary tumour-transforming 3, pseudogene (PTTG3P) in gastric cancer (GC) remains unknown. Here, we showed that PTTG3P expression was abnormally up-regulated in GC tissues compared with that in normal tissues both in our 198 cases of clinical samples and the cohort from The Cancer Genome Atlas (TCGA) database. High PTTG3P expression was correlated with increased tumour size and enhanced tumour invasiveness and served as an independent negative prognostic predictor. Moreover, up-regulation of PTTG3P in GC cells stimulated cell proliferation, migration and invasion both in vitro in cell experiments and in vivo in nude mouse models, and the pseudogene functioned independently of its parent genes. Overall, these results reveal that PTTG3P is a novel prognostic biomarker with independent oncogenic functions in GC. [ABSTRACT FROM AUTHOR]

Pressurized pipeline system damage is primarily caused by the highly destructive water hammer force. Currently, research on water hammer-caused collapse is mostly based on single-point collapse cases, but water hammer research, which involves multipoint collapse, is insufficient. Here, we establish an experimental platform to realize water hammers with multipoint collapse. With different schemes, i.e., various initial flow rates and valve closing speeds, we observed the hydraulic transient process with a high-speed camera, analyzed its characteristics and explained experimental phenomena with theoretical knowledge. Using experimental data analysis, we summarized the influencing factors and laws of the cavity length and water hammer pressure. Flow and pressure data for the different schemes were recorded to provide basic simulation data. Water column separation experimental phenomena were observed: completely atomized, completely cavitated and partially cavitated, and both cavitated and atomized. At the pump outlet, three hydraulic transition states occurred simultaneously in the horizontal pipe section: completely atomized, completely cavitated, and both cavitated and atomized. Two hydraulic transition states occurred in the knee region: completely and partially cavitated, and without atomization. The experimental results reveal that the initial flow rate and valve closing speed greatly affect the water hammer pressure rise and cavity length. The higher the initial flow rate and valve closing speed are, the larger the water hammer pressure rise and cavity length are. [ABSTRACT FROM AUTHOR]

The traditional discrete vapor cavity model (DVCM) is widely used in water hammer simulation. Water column separation in pipelines is usually predicted with this model. Nevertheless, the main weaknesses of this model consist of numerical instability and nonconvergence. Regarding the weaknesses of the traditional model, this paper discusses an improved method. The new method uses a new water hammer velocity formula, a new cavity model, and a floating grid method. Through simulations to test the effects of the new model, an experimental platform can be established to realize a water hammer with multipoint collapsing. The numerical simulation was programmed in C++ and the test was carried out with an actual pipeline model built in the laboratory. After certain modelling and calibration, the parameters in the simulation calculation were consistent with the measured parameters in the test. The numerical simulation results were compared with the experimental results. For the hydraulic transient system with multipoint collapsing, the superposition effect of the wave crest of the pseudo-water hammer in the traditional calculation model was obvious. The pressure of the water hammer in the simulation calculation was significantly higher than the actual value and the convergence effect of the water hammer wave was not good. Compared with the results of the traditional model, the simulation results of the new model were closer to the measured values. Therefore, the new model has better numerical solution accuracy, stability, and convergence, which is worth further study and promotion. [ABSTRACT FROM AUTHOR]

Polarization‐sensitive photodetection in the UV region is highly indispensable in many military and civilian applications. UV‐polarized photodetection usually relies on the use of wide bandgap semiconductors with 1D nanostructures requiring complicated nanofabrication processes. Although the emerging anisotropic 2D semiconductors shed light on the detection of polarization with a simple device architecture, bandgaps of such reported 2D semiconductors are too small to be applied for visible–blind UV‐polarized photodetection. Here, germanium disulfide (GeS2), the widest bandgap (>3 eV) in the family of in‐plane anisotropic 2D semiconductors explored to date, is introduced as an ideal candidate for UV‐polarized photodetection. The structural, vibrational, and optical anisotropies of GeS2 are systematically investigated from theory to experiment. GeS2‐based photodetectors show a strong polarization‐dependent photoresponse in the UV region. GeS2 with a wide bandgap and high in‐plane anisotropy not only enriches the family of anisotropic 2D semiconductors but also expands the polarized photodetection from the current visible and near‐infrared to the brand‐new UV region. [ABSTRACT FROM AUTHOR]

Germanium diselenide (GeSe2) has recently emerged as a new member of in‐plane anisotropic 2D materials, notable for its wide bandgap of 2.74 eV, excellent air stability, and high performance in polarization‐sensitive photodetection. However, the interlayer interaction in GeSe2 has never been reported, which usually plays an important role in layer‐number‐dependent physical properties. Here, the interlayer coupling in GeSe2 is systematically investigated from theory to experiment. Unexpectedly, all of density functional theory (DFT) calculations about layer‐dependent band structures, cleavage energy, binding energy, translation energy, and interlayer differential charge density demonstrate the much weaker interlayer interaction in GeSe2 when compared with black phosphorus (BP). Furthermore, both thickness‐dependent and temperature‐dependent Raman spectra of GeSe2 flakes, which exhibit no detectable changes of Raman peaks with the increase in thickness and a small first‐order temperature coefficient of −0.0095 cm−1 K−1, respectively, experimentally confirm the weakly coupled layers in GeSe2. The results establish GeSe2 as an unusual member of in‐plane anisotropic 2D materials with weak interlayer interaction. The ultraweak interlayer interaction in anisotropic GeSe2 is reported here. Azimuth‐dependent reflectance difference microscopy (ADRDM) verifies in‐plane anisotropy of GeSe2. DFT calculations including layer‐dependent band structures, cleavage energy, binding energy, translation energy, and interlayer differential charge density confirm weak interlayer interaction in GeSe2, which is further demonstrated by experimental studies, such as thickness‐dependent and temperature‐dependent Raman spectra. [ABSTRACT FROM AUTHOR]

As a new member of 2D materials, GeSe has attracted considerable attention recently due to its fascinating in‐plane anisotropic vibrational, electrical, and optical properties originating from the low‐symmetry crystal structure. Among these anisotropic properties, the anisotropic optical property, as a new degree of freedom to manipulate optoelectronic properties in 2D materials, is of great importance for practical applications. However, the fundamental understanding of the optical anisotropy of GeSe is still under exploration, severely restricting its utility in polarization‐sensitive optical systems. Here, a systematic study about the in‐plane optical anisotropy of GeSe is reported, including its anisotropic optical absorption, reflection, extinction, and refraction. The anisotropic band structure of GeSe is experimentally observed for the first time through angle‐resolved photoemission spectroscopy, explaining the origin of the optical anisotropy. The anisotropic reflection and refraction of GeSe are further directly visualized through the angle‐dependent optical contrast of GeSe flakes by azimuth‐dependent reflectance difference microscopy and polarization‐resolved optical microscopy, respectively. Finally, GeSe‐based photodetectors exhibit a polarization‐sensitive photoresponsivity due to the intrinsic linear dichroism. This study provides fundamental information for the optical anisotropy of GeSe, forcefully stimulating the exploration of novel GeSe‐based optical and optoelectronic applications. In‐plane optical anisotropy of GeSe is systematically studied by angle‐resolved photoemission spectroscopy, azimuth‐dependent reflectance difference microscopy, and polarization‐resolved optical microscopy, thus providing fundamental information for the optical anisotropy of GeSe and stimulating the exploration of novel GeSe‐based optical and optoelectronic applications. [ABSTRACT FROM AUTHOR]

As an emerging promising photovoltaic absorber material, GeSe has attracted significant interest recently due to its simple binary composition, attractive optical and electrical properties as well as earth‐abundant and low‐toxic constituents. However, no systematic study on the absorption property tuning of GeSe has been reported. Here, first it is shown that the crystallization temperature of amorphous GeSe is about 330 °C through differential thermal analysis and temperature‐dependent X‐ray diffraction. Next, GeSe films with tunable absorption property in the range of 1.79–1.14 eV are fabricated by annealing amorphous GeSe films at different temperatures. Finally, through the combined analysis of bandgaps measured by transmission spectroscopy and nanosheet thickness characterized by cross‐sectional high‐resolution transmission electron microscopy, the blue shift of bandgap with decreasing thickness of nanosheets has been attributed to the quantum confinement effect. Such continuously tunable absorption property of GeSe films makes it more useful for further optoelectronics. A controllable absorption property tuning of GeSe films in the range of 1.79–1.14 eV through annealing treatment of amorphous GeSe films has been demonstrated. Such continuously tunable absorption property of GeSe films makes it more useful for further optoelectronics. [ABSTRACT FROM AUTHOR]