Multilevel Conductance States of Vapor-Transport-Deposited Sb2S3 Memristors Achieved via Electrical and Optical Modulation.

The pursuit of advanced brain-inspired electronic devices and memory technologies has led to explore novel materials by processing multimodal and multilevel tailored conductive properties as the next generation of semiconductor platforms, due to von Neumann architecture limits. Among such materials, antimony sulfide (Sb2S3) thin films exhibit outstanding optical and electronic properties, and therefore, they are ideal for applications such as thin-film solar cells and nonvolatile memory systems. This study investigates the conduction modulation and memory functionalities of Sb2S3 thin films deposited via the vapor transport deposition technique. Experimental results indicate that the Ag/Sb2S3/Pt device possesses properties suitable for memory applications, including low operational voltages, robust endurance, and reliable switching behavior. Further, the reproducibility and stability of these properties across different device batches validate the reliability of these devices for practical implementation. Moreover, Sb2S3-based memristors exhibit artificial neuroplasticity with prolonged stability, promising considerable advancements in neuromorphic computing. Leveraging the photosensitivity of Sb2S3 enables the Ag/Sb2S3/Pt device to exhibit significant low operating potential and conductivity modulation under optical stimulation for memory applications. This research highlights the potential applications of Sb2S3 in future memory devices and optoelectronics and in shaping electronics with versatility.

Promotion of Probabilistic Bit Generation in Mott Devices by Embedded Metal Nanoparticles.

Considerable attention has been drawn to the use of volatile two-terminal devices relying on the Mott transition for the stochastic generation of probabilistic bits (p-bits) in emerging probabilistic computing. To improve randomness and endurance of bit streams provided by these devices, delicate control of the transient evolution of switchable domains is required to enhance stochastic p-bit generation. Herein, it is demonstrated that the randomness of p-bit streams generated via the consecutive pulse inputs of pump-probe protocols can be increased by the deliberate incorporation of metal nanoparticles (NPs), which influence the transient dynamics of the nanoscale metallic phase in VO2 Mott switches. Among the vertically stacked Pt-NP-containing VO2 threshold switches, those with higher Pt NP density show a considerably wider range of p-bit operation (e.g., up to ≈300% increase in ΔVprobe upon going from (Pt NP/VO2)0 to (Pt NP/VO2)11) and can therefore be operated under the conditions of high speed (400 kbit s-1), low power consumption (14 nJ per bit), and high stability (>105 200 bits) for p-bit generation. Thus, the study presents a novel strategy that exploits nanoscale phase control to maximize the generation of nondeterministic information sources for energy-efficient probabilistic computing hardware.

Fostering Charge Carrier Transport and Absorber Growth Properties in CZTSSe Thin Films with an ALD-SnO2 Capping Layer.

The present study demonstrates that precursor passivation is an effective approach for improving the crystallization process and controlling the detrimental defect density in high-efficiency Cu2ZnSn(S,Se)4 (CZTSSe) thin films. It is achieved by applying the atomic layer deposition (ALD) of the tin oxide (ALD-SnO2) capping layer onto the precursor (Cu-Zn-Sn) thin films. The ALD-SnO2 capping layer was observed to facilitate the homogeneous growth of crystalline grains and mitigate defects prior to sulfo-selenization in CZTSSe thin films. Particularly, the CuZn and SnZn defects and deep defects associated with Sn were effectively mitigated due to the reduction of Sn2+ and the increase in Sn4+ levels in the kesterite CZTSSe film after introducing ALD-SnO2 on the precursor films. Subsequently, devices integrating the ALD-SnO2 layer exhibited significantly reduced recombination and efficient charge transport at the heterojunction interface and within the bulk CZTSSe absorber bulk properties. Finally, the CZTSSe device showed improved power conversion efficiency (PCE) from 8.46% to 10.1%. The incorporation of ALD-SnO2 revealed reduced defect sites, grain boundaries, and surface roughness, improving the performance. This study offers a systematic examination of the correlation between the incorporation of the ALD-SnO2 layer and the improved PCE of CZTSSe thin film solar cells (TFSCs), in addition to innovative approaches for improving absorber quality and defect control to advance the performance of kesterite CZTSSe devices.

Defect engineered ternary metal spinel-type Ni-Fe-Co oxide as bifunctional electrocatalyst for overall electrochemical water splitting.

Transition metal spinel oxides were engineered with active elements as bifunctional water splitting electrocatalysts to deliver superior intrinsic activity, stability, and improved conductivity to support green hydrogen production. In this study, we reported the ternary metal Ni-Fe-Co spinel oxide electrocatalysts prepared by defect engineering strategy with rich and deficient Na+ ions, termed NFCO-Na and NFCO, which suggest the formation of defects with Na+ forming tensile strain. The Na-rich NiFeCoO4 spinel oxide reveals lattice expansion, resulting in the formation of a defective crystal structure, suggesting higher electrocatalytic active sites. The spherical NFCO-Na electrocatalysts exhibit lower OER and HER overpotentials of 248 mV and 153 mV at 10 mA cm-2 and smaller Tafel slope values of about 78 mV dec-1 and 129 mV dec-1, respectively. Notably, the bifunctional NFCO-Na electrocatalyst requires a minimum cell voltage of about 1.67 V to drive a current density of 10 mA cm-2. The present work highlights the significant electrochemical activity of defect-engineered ternary metal oxides, which can be further upgraded as highly active electrocatalysts for water splitting applications.

Structurally engineered highly efficient electrocatalytic performance of 3-dimensional Mo/Ni chalcogenides for boosting overall water splitting performance.

Hydrogen production from water splitting combined with renewable electricity can provide a viable solution to the energy crisis. A novel MoS2/NiS2/Ni3S4 heterostructure is designed as a bifunctional electrocatalyst by facile hydrothermal method to demonstrate excellent electrocatalytic performance towards overall water splitting applications. MoS2/NiS2/Ni3S4 heterostructure necessitates a low overpotential of 81 mV and 210 mV to attain a current density of 10 mA cm-2 during the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Consequently, the MoS2/NiS2/Ni3S4 heterostructure-based electrolyzer shows a low cell voltage of 1.54 V at 10 mA cm-2. The present work highlights the significance of the heterostructure configuration of transition metal sulfide-based electrocatalysts for electrochemical overall water splitting applications.

2 DOF transformable wheel design based on geared 8 bar parallel linkage mechanism.

This paper introduces a novel design and static optimization for a two-degrees-of-freedom transformable wheel based on a geared linkage mechanism. Overcoming obstacles, including stairs, with small wheels is a major challenge in the field of mobile robotics research. Among various robots, the transformable wheel, which can change the shape of the wheel to overcome steps and optimize the path, was presented and has undergone many improvements. Nevertheless, problems such as asymmetry and structural strength remain. Therefore, the design of this paper aims to address the structural inefficiencies identified in the previous research model, which were attributed to the asymmetric placement of the linear motion guide. Through the implementation of this mechanism, the linear motion of the lobe can be segregated, enabling each input motor to share the workload effectively. The optimization process focus on determining the optimal linkage length under static conditions, resulting in improved structural characteristics and force distribution of linkage within the designated workspace. As a result, asymmetry of motion is eliminated, required intervention angle of the driving motor and stress of linkage was reduced by 36.24% and 8.35%, respectively.

Cs-treatments in Kesterite Thin-Film Solar Cells for Efficient Perovskite Tandems.

Cu2ZnSn(S,Se)4 (CZTSSe) thin film solar cells are an attractive choice for a bottom cell of the low-cost and environmental tandem solar cells with perovskite. However, the progress in developing efficient perovskite/CZTSSe tandem solar cells has been hindered by the lack of high performance of the CZTSSe bottom cell. Here, an efficient CZTSSe bottom cell is demonstrated by adopting a facile and effective CsF treatment process. It is found that the CsF treatment not only facilitates grain growth and improves phase homogeneity by suppressing the detrimental deep-level defects and secondary phases, but also induces larger band bending and stronger drift force at the P-N junction. As a result, the carrier extraction/transport can be effectively accelerated, while reducing the interfacial recombination. These combined effects eventually result in a significant performance enhancement from 8.38% to 10.20%. The CsF-treated CZTSSe solar cell is finally applied to the mechanically-stacked perovskite/CZTSSe 4-terminal tandem cell by coupling a semi-transparent perovskite top cell, which exhibits the highest reported tandem efficiency of 23.01%.

Novel Mg- and Ga-doped ZnO/Li-Doped Graphene Oxide Transparent Electrode/Electron-Transporting Layer Combinations for High-Performance Thin-Film Solar Cells.

Herein, a novel combination of Mg- and Ga-co-doped ZnO (MGZO)/Li-doped graphene oxide (LGO) transparent electrode (TE)/electron-transporting layer (ETL) has been applied for the first time in Cu2 ZnSn(S,Se)4 (CZTSSe) thin-film solar cells (TFSCs). MGZO has a wide optical spectrum with high transmittance compared to that with conventional Al-doped ZnO (AZO), enabling additional photon harvesting, and has a low electrical resistance that increases electron collection rate. These excellent optoelectronic properties significantly improved the short-circuit current density and fill factor of the TFSCs. Additionally, the solution-processable alternative LGO ETL prevented plasma-induced damage to chemical bath deposited cadmium sulfide (CdS) buffer, thereby enabling the maintenance of high-quality junctions using a thin CdS buffer layer (≈30 nm). Interfacial engineering with LGO improved the Voc of the CZTSSe TFSCs from 466 to 502 mV. Furthermore, the tunable work function obtained through Li doping generated a more favorable band offset in CdS/LGO/MGZO interfaces, thereby, improving the electron collection. The MGZO/LGO TE/ETL combination achieved a power conversion efficiency of 10.67%, which is considerably higher than that of conventional AZO/intrinsic ZnO (8.33%).

Paget-Schroetter syndrome from manual handling at work: Case report and review of the literature.

Paget-Schroetter syndrome (PSS) is a primary deep venous thrombosis of the subclavian-axillary vein complex occurring after repetitive and strenuous use of the shoulders and arms. Here, we report the case of a 24-year-old man who presented with left subclavian and axillary vein thrombosis after loading and unloading labor, who was diagnosed with PSS confirmed with Doppler ultrasound, and treated with anticoagulation. By comparing our case with 45 published case reports, we also aim to analyze patient characteristics, diagnostic methods, and treatment options for the disorder.

A Modified CAIDE Risk Score as a Screening Tool for Cognitive Impairment in Older Adults.

BACKGROUND: Although an efficacious dementia-risk score system, Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) was derived using midlife risk factors in a population with low educational attainment that does not reflect today's US population, and requires laboratory biomarkers, which are not always available. OBJECTIVE: Develop and validate a modified CAIDE (mCAIDE) system and test its ability to predict presence, severity, and etiology of cognitive impairment in older adults. METHODS: Population consisted of 449 participants in dementia research (N = 230; community sample; 67.9±10.0 years old, 29.6%male, 13.7±4.1 years education) or receiving dementia clinical services (N = 219; clinical sample; 74.3±9.8 years old, 50.2%male, 15.5±2.6 years education). The mCAIDE, which includes self-reported and performance-based rather than blood-derived measures, was developed in the community sample and tested in the independent clinical sample. Validity against Framingham, Hachinski, and CAIDE risk scores was assessed. RESULTS: Higher mCAIDE quartiles were associated with lower performance on global and domain-specific cognitive tests. Each one-point increase in mCAIDE increased the odds of mild cognitive impairment (MCI) by up to 65%, those of AD by 69%, and those for non-AD dementia by > 85%, with highest scores in cases with vascular etiologies. Being in the highest mCAIDE risk group improved ability to discriminate dementia from MCI and controls and MCI from controls, with a cut-off of ≥7 points offering the highest sensitivity, specificity, and positive and negative predictive values. CONCLUSION: mCAIDE is a robust indicator of cognitive impairment in community-dwelling seniors, which can discriminate well between dementia severity including MCI versus controls. The mCAIDE may be a valuable tool for case ascertainment in research studies, helping flag primary care patients for cognitive testing, and identify those in need of lifestyle interventions for symptomatic control.

Atomic Layer Deposition of ZrO2 on Titanium Inhibits Bacterial Adhesion and Enhances Osteoblast Viability.

PURPOSE: The study was intended to create a uniform zirconia layer even on the surface of complex structures via atomic layer deposition (ALD). The impact of crystalline zirconia deposited by ALD on bacterial adhesion and osteoblast viability was assessed via surface treatment of dental implants. METHODS: Amorphous zirconia was deposited using an atomic layer deposition reactor (Atomic Classic, CN1, Hwaseong, Korea) on titanium discs. Heating the samples at 400°C resulted in crystallization. Samples were divided into three groups: the control group, the group carrying amorphous ALD-zirconia (Z group), and the heat-treated group following zirconia ALD deposition (ZH group).The surface of each sample was analyzed, followed by the assessment of adhesion of Streptococcus mutans and Porphyromonas gingivalis, and viability and differentiation of MC3T3-E1 cells. RESULTS: The adhesion of S. mutans and P. gingivalis was significantly reduced in the Z and ZH groups compared with the control group (P < 0.05). The viability of MC3T3-E1 cells was significantly increased in the ZH group compared with the control group (P < 0.001), while no significant differences were observed in the Z group (P > 0.05). Differentiation of MC3T3-E1 cells showed a marginally significant increase in the ZH group compared with the control group (P < 0.1), while no significant differences were found in the Z group (P > 0.1). CONCLUSION: Compared with the pure titanium group, the groups that were coated with zirconia via ALD showed a decreased adhesion of S. mutans during the early stages of biofilm formation and P. gingivalis adhesion inducing peri-implantitis, and an increase in MC3T3-E1 cell viability and differentiation. The findings indicate the possibility of treating the implant surface to reduce peri-implantitis and improve osseointegration.

Atomic layer deposition of Al2O3 on P2-Na0.5Mn0.5Co0.5O2 as interfacial layer for high power sodium-ion batteries.

Surface modification is one of the impressive and widely used technique to improve the electrochemical performance of sodium-ion batteries by modifying the electrode-electrolyte interface. Herein, we used the atomic layer deposition (ALD) to modify the surface of P2-Na0.5Mn0.5Co0.5O2 by sub-monolayer Al2O3 coating on the prefabricated electrodes. Phase purity is confirmed using various structural and morphological studies. The pristine electrode delivered an initial discharge capacity of 154 mAh g-1 at 0.5C, and inferior rate performance of 23 mAh g-1 at 40C rate. On the other hand, the interfacial modified cathode with 5 cycles of ALD coating delivers a high capacity of 174 and 45 mAh g-1 at 0.5C and 40C rate, respectively. The Co2+/3+ redox couple is utilized for the faradaic process with high reversibility along with suppressed P2-O2 phase transition. The presence of the Al2O3 layer acts as an artificial cathode electrolyte interface by suppressing the electrolyte oxidation at higher cutoff potentials. This is clearly validated by the reduced charge transfer resistance of surface modified electrodes after cycling at various current rates. Even at an elevated temperature condition (50 °C), interfacial layer significantly improves the safety of the cell and ensures the stability of the cathode.

Phase identification of vanadium oxide thin films prepared by atomic layer deposition using X-ray absorption spectroscopy.

The chemical and local structures of vanadium oxide (VO x ) thin films prepared by atomic layer deposition (ALD) were investigated by soft X-ray absorption spectroscopy. It is shown that the as-deposited film was a mixture of VO2 and V2O5 in disordered form, while the chemistry changed significantly after heat treatment, subject to the different gas environment. Forming gas (95% N2 + 5% H2) annealing resulted in a VO2 composition, consisting mostly of the VO2 (B) phase with small amount of the VO2 (M) phase, whereas O2 annealing resulted in the V2O5 phase. An X-ray circular magnetic dichroism study further revealed the absence of ferromagnetic ordering, confirming the absence of oxygen vacancies despite the reduction of V ions in VO2 (V4+) with respect to the precursor used in the ALD (V5+). This implies that the prevalence of VO2 in the ALD films cannot be attributed to a simple oxygen-deficiency-related reduction scheme but should be explained by the metastability of the local VO2 structures.

Solution-Processed ZnxCd1-xS Buffer Layers for Vapor Transport-Deposited SnS Thin-Film Solar Cells: Achieving High Open-Circuit Voltage.

As an alternative buffer material to CdS, ZnxCd1-xS buffer layers for vapor transport-deposited SnS thin-film solar cells (TFSCs) were fabricated using the successive ionic layer adsorption and reaction (SILAR) method. Varying the Zn-to-Cd ratio resulted in a series of ZnxCd1-xS thin films with controllable band gaps in the range of 2.40-3.65 eV. The influence of the Zn-to-Cd ratio on the cell performance was investigated in detail. The Zn0.34Cd0.66S buffer layer was found to be the optimal composition for SnS TFSCs, and a record open-circuit voltage (Voc) of 0.405 V was achieved with an efficiency of 3.72%, whereas the SILAR-CdS buffer layer rendered a Voc of 0.324 V. The improvement in Voc when using the Zn0.34Cd0.66S buffer layer was corroborated by the spike-type conduction band offset of 0.35 eV with the SnS absorber, as revealed by the X-ray photoelectron spectroscopy analysis. In addition, minimized interfacial recombination at the SnS/Zn0.34Cd0.66S heterojunction was confirmed by the temperature-dependent Voc analysis under illuminated conditions.

Revealing the Simultaneous Effects of Conductivity and Amorphous Nature of Atomic-Layer-Deposited Double-Anion-Based Zinc Oxysulfide as Superior Anodes in Na-Ion Batteries.

Although sodium-ion batteries (SIBs) are considered promising alternatives to their Li counterparts, they still suffer from challenges like slow kinetics of the sodiation process, large volume change, and inferior cycling stability. On the other hand, the presence of additional reversible conversion reactions makes the metal compounds the preferred anode materials over carbon. However, conductivity and crystallinity of such materials often play the pivotal role in this regard. To address these issues, atomic layer deposited double-anion-based ternary zinc oxysulfide (ZnOS) thin films as an anode material in SIBs are reported. Electrochemical studies are carried out with different O/(O+S) ratios, including O-rich and S-rich crystalline ZnOS along with the amorphous phase. Amorphous ZnOS with the O/(O+S) ratio of ≈0.4 delivers the most stable and considerably high specific (and volumetric) capacities of 271.9 (≈1315.6 mAh cm-3 ) and 173.1 mAh g-1 (≈837.7 mAh cm-3 ) at the current densities of 500 and 1000 mA g-1 , respectively. A dominant capacitive-controlled contribution of the amorphous ZnOS anode indicates faster electrochemical reaction kinetics. An electrochemical reaction mechanism is also proposed via X-ray photoelectron spectroscopy analyses. A comparison of the cycling stability further establishes the advantage of this double-anion-based material over pristine ZnO and ZnS anodes.

Pro-Inflammatory Role of S1P3 in Macrophages.

Sphingosine kinase 1 and its product, sphingosine 1-phosphate (S1P), as well as their receptors, have been implicated in inflammatory responses. The functions of receptors S1P1 and S1P2 on cell motility have been investigated. However, the function of S1P3 has been poorly investigated. In this study, the roles of S1P3 on inflammatory response were investigated in primary peritoneal macrophages. S1P3 receptor was induced along with sphingosine kinase 1 by stimulation of lipopolysaccharide (LPS). LPS treatment induced inflammatory genes, such iNOS, COX-2, IL-1ß, IL-6 and TNF-α. TY52156, an antagonist of S1P3 suppressed the induction of inflammatory genes in a concentration dependent manner. Suppression of iNOS and COX-2 induction was further confirmed by western blotting and NO measurement. Suppression of IL-1ß induction was also confirmed by western blotting and ELISA. Caspase 1, which is responsible for IL-1ß production, was similarly induced by LPS and suppressed by TY52156. Therefore, we have shown S1P3 induction in the inflammatory conditions and its pro-inflammatory roles. Targeting S1P3 might be a strategy for regulating inflammatory diseases.

Anti-allergic effects of salvianolic acid A and tanshinone IIA from Salvia miltiorrhiza determined using in vivo and in vitro experiments.

Salvia miltiorrhiza root has been used in Asian traditional medicine for the treatment of cardiovascular diseases, asthma, and other conditions. Salvianolic acid B from S. miltiorrhiza extracts has been shown to improve airway hyperresponsiveness. We investigated the effects of salvianolic acid A, tanshinone I, and tanshinone IIA from S. miltiorrhiza in allergic asthma by using rat RBL-2H3 mast cells and female Balb/c mice. Antigen-induced degranulation was assessed by measuring ß-hexosaminidase activity in vitro. In addition, a murine ovalbumin-induced allergic asthma model was used to test the in vivo efficacy of salvianolic acid A and tanshinone IIA. Tanshinone I and tanshinone IIA inhibited antigen-induced degranulation of mast cells, but salvianolic acid A did not. Administration of salvianolic acid A and tanshinone IIA decreased the number of immune cells, particularly eosinophils in allergic asthma-induced mice. Histological studies showed that salvianolic acid A and tanshinone IIA reduced mucin production and inflammation in the lungs. Administration of salvianolic acid A and tanshinone IIA reduced the expression and secretion of Th2 cytokines (IL-4 and IL-13) in the bronchoalveolar lavage fluid and lung tissues of mice with ovalbumin-induced allergic asthma. These findings provide evidence that salvianolic acid A and tanshinone IIA may be potential anti-allergic therapeutics.

A Phosphosilicate Compound, NaCa3PSiO8: Structure Solution and Luminescence Properties.

NaCa3PSiO8 was synthesized in a microwave-assisted solid-state reaction. The crystal structure of the synthesized compound was solved using a least-squares method, followed by simulated annealing. The compound was crystallized in the orthorhombic space group Pna21, belonging to Laue class mmm. The structure consisted of two layers of cation planes, each of which contained three cation channels. The cation channels in each of the layers ran antiparallel to that of the adjacent layer. All the major cations together constituted four distinct crystallographic sites. The Rietveld refinement of the powder X-ray diffraction data, followed by the maximum-entropy method analysis, confirmed the obtained structure solutions. The electronic band structure of the compound was analyzed through density function theory calculations. Luminescence properties of the compound, upon activating with Eu2+ ions, were analyzed through photoluminescence measurements and decay profile analysis. The compound was found to exhibit green luminescence centered at ∼502 nm, with a typical broadband emission due to the transition from the crystal-field split 4f65d to 4f7 levels.

Highly Uniform Atomic Layer-Deposited MoS2@3D-Ni-Foam: A Novel Approach To Prepare an Electrode for Supercapacitors.

This article takes an effort to establish the potential of atomic layer deposition (ALD) technique toward the field of supercapacitors by preparing molybdenum disulfide (MoS2) as its electrode. While molybdenum hexacarbonyl [Mo(CO)6] serves as a novel precursor toward the low-temperature synthesis of ALD-grown MoS2, H2S plasma helps to deposit its polycrystalline phase at 200 °C. Several ex situ characterizations such as X-ray diffractometry (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and so forth are performed in detail to study the as-grown MoS2 film on a Si/SiO2 substrate. While stoichiometric MoS2 with very negligible amount of C and O impurities was evident from XPS, the XRD and high-resolution transmission electron microscopy analyses confirmed the (002)-oriented polycrystalline h-MoS2 phase of the as-grown film. A comparative study of ALD-grown MoS2 as a supercapacitor electrode on 2-dimensional stainless steel and on 3-dimensional (3D) Ni-foam substrates clearly reflects the advantage and the potential of ALD for growing a uniform and conformal electrode material on a 3D-scaffold layer. Cyclic voltammetry measurements showed both double-layer capacitance and capacitance contributed by the faradic reaction at the MoS2 electrode surface. The optimum number of ALD cycles was also found out for achieving maximum capacitance for such a MoS2@3D-Ni-foam electrode. A record high areal capacitance of 3400 mF/cm2 was achieved for MoS2@3D-Ni-foam grown by 400 ALD cycles at a current density of 3 mA/cm2. Moreover, the ALD-grown MoS2@3D-Ni-foam composite also retains high areal capacitance, even up to a high current density of 50 mA/cm2. Finally, this directly grown MoS2 electrode on 3D-Ni-foam by ALD shows high cyclic stability (>80%) over 4500 charge-discharge cycles which must invoke the research community to further explore the potential of ALD for such applications.

Chemically Deposited CdS Buffer/Kesterite Cu2ZnSnS4 Solar Cells: Relationship between CdS Thickness and Device Performance.

Earth-abundant, copper-zinc-tin-sulfide (CZTS), kesterite, is an attractive absorber material for thin-film solar cells (TFSCs). However, the open-circuit voltage deficit (Voc-deficit) resulting from a high recombination rate at the buffer/absorber interface is one of the major challenges that must be overcome to improve the performance of kesterite-based TFSCs. In this paper, we demonstrate the relationship between device parameters and performances for chemically deposited CdS buffer/CZTS-based heterojunction TFSCs as a function of buffer layer thickness, which could change the CdS/CZTS interface conditions such as conduction band or valence band offsets, to gain deeper insight and understanding about the Voc-deficit behavior from a high recombination rate at the CdS buffer/kesterite interface. Experimental results show that device parameters and performances are strongly dependent on the CdS buffer thickness. We postulate two meaningful consequences: (i) Device parameters were improved up to a CdS buffer thickness of 70 nm, whereas they deteriorated at a thicker CdS buffer layer. The Voc-deficit in the solar cells improved up to a CdS buffer thickness of 92 nm and then deteriorated at a thicker CdS buffer layer. (ii) The minimum values of the device parameters were obtained at 70 nm CdS thickness in the CZTS TFSCs. Finally, the highest conversion efficiency of 8.77% (Voc: 494 mV, Jsc: 34.54 mA/cm2, and FF: 51%) is obtained by applying a 70 nm thick CdS buffer to the Cu2ZnSn(S,Se)4 absorber layer.