Charge Carriers Research Articles

Intrinsically Slow Cooling of Hot Electrons in CdSe Nanocrystals Compared to CdS.

The utilization of excited charge carriers in semiconductor nanocrystals (NCs) for optoelectronic technologies has been a long-standing goal in the field of nanoscience. Experimental efforts to extend the lifetime of excited carriers have therefore been a principal focus. To understand the limits of these lifetimes, in this work, we theoretically study the time scales of pure electron relaxation in negatively charged NCs composed of two prototypical materials: CdSe and CdS. We find that hot electrons in CdSe have lifetimes that are 5 to 6 orders of magnitude longer than in CdS when the relaxation is governed only by the intrinsic properties of the materials. Although these two materials are known to have somewhat different electronic structure, we elucidate how this enormous difference in lifetimes arises from relatively small quantitative differences in electronic energy gaps and phonon frequencies, as well as the crucial role of Fröhlich-type electron-phonon couplings.

Integrating Experimental and Computational Insights: A Dual Approach to Ba2CoWO6 Double Perovskites

Double perovskite materials have emerged as key players in the realm of advanced materials due to their unique structural and functional properties. This research mainly focuses on the synthesis and comprehensive characterization of Ba2CoWO6 double perovskite nanopowders utilizing a high-temperature conventional solid-state reaction technique. The successful formation of Ba2CoWO6 powders was confirmed through detailed analysis employing advanced characterization techniques. Rietveld refinement of X-ray diffraction (XRD) and Raman data established that Ba2CoWO6 crystallizes in a cubic crystal structure with the space group Fm-3m, indicative of a highly ordered perovskite lattice. The typical crystallite size, approximately 65 nm, highlights the nanocrystalline nature of the material. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) discovered a distinctive morphology characterized by spherical shaped particles, suggesting a complex particle formation process influenced by synthesis conditions. To probe the electronic structure, X-ray Photoelectron Spectroscopy (XPS) identified cobalt and tungsten valence states, critical for understanding dielectric properties associated with localized charge carriers. The semiconducting character of the synthesized Ba2CoWO6 nanocrystalline material was confirmed through UV-Visible analysis, which revealed an energy bandgap value of 3.3 eV, which aligns well with the theoretical predictions, indicating the accuracy and reliability of the experimental results. The photoluminescence spectrum exhibited two distinct emissions in the blue-green region. These emissions were attributed to the transitions 3P0→3H4, 3P0→3H5, and 3P0→3H6, primarily resulting from the contributions of Ba2+ ions. The dielectric characteristics of the compound were analyzed across a different range of frequencies, spanning from 1 kHz to 1 MHz. Magnetic characterization using Vibrating Sample Magnetometry (VSM) revealed antiferromagnetic behavior of Ba2CoWO6 ceramics at room temperature, attributed to super-exchange interactions between Co3+ and W5+ ions mediated by oxygen ions in the perovskite lattice. Additionally, first-principles calculations based on the Generalized Gradient Approximation (GGA+U) with a modified Becke–Johnson (mBJ) potential were employed to gain a deeper understanding of the structural and electronic properties of the materials. This approach involved systematically varying the Hubbard U parameter to optimize the description of electron correlation effects. These results deliver an extensive understanding of the structural, optical, morphological, electronic, and magnetic properties of Ba2CoWO6 ceramics, underscoring their potential for electronic and magnetic device applications.

Photocatalytic Depolymerization of Lignin: C-O Bond Cleavage in β-O-4 Models Using S-Doped Ultra-Thin Bi3O4Cl Nanosheets

The selective depolymerization of β-O-4 lignin models into high-value aromatic monomers using photocatalysis presents both significant opportunities and challenges. Photocatalysts often face issues such as high photogenerated carrier recombination rates and limited operational lifetimes. This study introduces S doping to modulate the surface interface of Bi3O4Cl (BOC) nanosheets, enhancing C-O bond cleavage efficiency in β-O-4 lignin models under visible light at ambient temperatures. Comprehensive characterization, including atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), electron spin resonance (ESR), and density functional theory (DFT) analysis, revealed that S doping reduces BOC nanosheet thickness to 1.51 nm and promotes charge carrier separation, thereby generating greater concentrations of reactive species, specifically •O2− and •OH. Photocatalytic depolymerization experiments demonstrated that S-doped BOC achieved a C-O bond cleavage selectivity of 93% and an aromatic monomer yield of 629.03 μmol/g/h (i.e., 1.5 times higher than that of undoped BOC). This work provides a strategic approach to designing photocatalysts with enhanced selectivity and efficiency for lignin depolymerization.

Effect of Strain on the Photocatalytic Reaction of Graphitic Carbon Nitride: Insight from Single-Molecule Localization Microscopy.

Strain engineering in two-dimensional nanomaterials holds significant potential for modulating the lattice and band structure, particularly through localized strain, which enables modulation at specific regions. Despite the remarkable effects of local strain, the relationships among local strain, spatial correlation of photogenerated charge carriers, and photocatalytic performance remain elusive. The current study coupled single-molecule localization microscopy with coordinate-based colocalization (CBC) analysis to explain these relationships. The methodology involved mapping the spatial distributions of photoinduced oxidation and reduction reaction sites across graphitic carbon nitride (g-C3N4) nanosheets, quantifying and spatially resolving their spatial correlation, and also evaluating their photocatalytic activity. The study examined 65 individual g-C3N4 nanosheets, revealing interparticle and intraparticle heterogeneity, which was classified based on their CBC score distributions. Among the 65 g-C3N4 nanosheets, type A nanosheets predominated (45 out of 65) and demonstrated both correlated and noncorrelated subregions along some wrinkles. In contrast, type B nanosheets (20 out of 65) were primarily characterized by noncorrelated subregions with minimal correlated localizations. The coexistence of both noncorrelated and correlated subregions inferred the structure of the wrinkles as folding wrinkles, which have larger tensile-strained areas than rippling wrinkles. Folding wrinkles promote colocalization through the formation of type I band alignment at tensile-strained subregions. This band alignment also enhances photocatalytic activity through a funneling effect and improved light absorption, leading to higher specific activity in correlated subregions compared to noncorrelated ones. The role of strain-induced band alignment in modulating the spatial correlation of the photoredox reaction and the photocatalytic performance at the subregion level is highlighted.

DLTS characterisation of 107 MeV krypton ion-irradiated nitrogen-doped 4H-silicon carbide

Swift heavy ions, such as krypton ions, play a significant role in developing and enhancing the performance of various devices. In this study, the influence of Kr2+ on nitrogen-doped 4H-silicon carbide has been investigated using deep level transient spectroscopy (DLTS). Krypton ions, with an energy of 107 MeV, were used to irradiate the Au/Ni/4H-SiC Schottky barrier diodes (SBDs) at a fluence of 1 × 1010 cm–2 at room temperature (300 K). Before the irradiation of the samples, the electrical measurements revealed good rectifying behaviour. However, rectification properties of the Au/Ni/4H-SiC SBDs were completely lost after irradiation at a fluence of 1 × 1010 cm–2. Annealing was performed at 300 °C in flowing argon, and the current–voltage (I–V) and capacitance–voltage (C–V) revealed partial rectification. DLTS of the as-grown devices analyses revealed the presence of four deep level defects. After annealing the irradiated device, the DLTS spectra showed a reduction in the intensity of the E0.10 and the disappearance of the E0.12 as well as the E0.16 defects compared to that as-grown. Two defects with energies of 280 and 410 meV showed inverted peaks, as would have been expected from minority carriers trap instead of majority carriers, which led to confusion as the peaks were inverted. It was concluded that the peculiar characteristics of DLTS measurements on SBDs may be due to the extremely high value of the series resistance as well as the low capacitance. The results of this study provide insight into the behaviour of SBDs under extreme irradiation and can be used to improve the radiation tolerance of electronic devices made from SiC.

Investigating Dopant Effects in ZnO as an Electron Transport Layer for Enhanced Efficiency in Organic Photovoltaics

AbstractThe power conversion efficiencies of organic solar cells greatly depend on the device architecture and choice of charge transporting materials. Improved power conversion efficiency (PCE) for inverted organic solar cells is observed when using Sn‐doped ZnO as the electron transporting layer. By doping the elements with different numbers of valence electrons (Al3+ and Sn4+ ions) into the ZnO matrix, device conversion efficiencies of 8.69% and 9.21%, respectively, are achieved. Conductive atomic force microscopy (CAFM) observations reveal that the Sn‐doped ZnO film exhibits better conductivity due to its larger number of carrier charges. X‐ray photoemission spectroscopy (XPS) indicates larger oxygen vacancies (OV) in Sn‐doped ZnO. Electrochemical characterization exhibits that there is a reduction in series resistance and charge transfer (CT) resistance for SZO, indicating the optimal charge transport capability of the electron transport layer (ETL). Ultrafast time‐resolved studies further show that, in comparison with Al‐doped ZnO and un‐doped ZnO, the elevated carrier concentration in Sn‐doped ZnO plays a significant role in augmenting the photocurrent. Thus, it is determined how dopants in ETL influence CT mechanisms, enhancing the photovoltaic conversion efficiency, thus contributing to the development of cost‐effective and efficient photovoltaic technologies.

Carboxymethyl‐Based Ionic Liquid Engineering for Efficient and Stable Inverted Perovskite Solar Cells

Perovskite solar cells (PSCs) have garnered significant attention due to their tunable bandgap, superior charge carrier properties, and easy fabrication processes, making them highly efficient energy conversion devices. Despite these advantages, nonradiative recombination due to defects in the perovskite layer continues to limit performance. This study addresses this issue by introducing 1‐CarboxyMethyl‐3‐MethylImidazolium chloride (ImAcCl) into precursor solution to enhance film quality and suppress defect‐induced recombination. The carboxylate groups (CO) and hydrogen donors (NH) in ImAcCl form coordination and hydrogen bonds, helping to reduce defect density of the perovskite film. Additive ImAcCl improves crystallinity, reduces surface roughness, and enhances charge carrier transport, leading to higher photovoltaic performance. With the ImAcCl additive, the power conversion efficiency and short‐circuit current of PSCs significantly improve by 23.92% and 25.35 mA cm−2, with a notable reduction in nonradiative recombination losses. This study highlights the significant potential of ImAcCl as an effective additive for defect passivation in PSCs, offering a promising pathway toward further efficiency improvements in next‐generation solar cells.

Construction of a 0D-2D-2D Sandwich-like Ag/g-C3N4/MoS2 Photocatalyst with Bidirectional Electron Transfer Channels for Photocatalytic Hydrogen Evolution.

Hydrogen (H2) production technology has sparked a boom in research aimed at alleviating environmental pollution and the pressure of nonrenewable energy sources. A key factor in this technology is the use of efficient photocatalysts. In this work, we successfully synthesized a 0D-2D-2D sandwich-like Ag/g-C3N4/MoS2 catalyst with bidirectional electron transfer channels via a calcination-hydrothermal method. The H2 evolution reaction of the Ag/g-C3N4/MoS2 catalyst under simulated solar light irradiation conditions revealed that it achieved a maximum H2 evolution rate of 1061.13 μmol·g-1·h-1, representing a 43.12-fold improvement over pristine g-C3N4. Based on systematic characterization with a combination of theoretical simulations, time-resolved photoluminescence, and electron spin resonance spectra, we demonstrate that the remarkable improvement in photocatalytic performance was ascribed to the bidirectional electron transport channels and 0D-2D-2D structure of the ternary catalyst. This unique structure, which was characterized by a large specific surface area, provided numerous active sites for photocatalytic reactions. Bidirectional electron transfer channels expedited the migration of photogenerated electrons reaching cocatalysts MoS2 and Ag from the conduction band of g-C3N4, consequently enhancing the photocatalytic activity. This study highlights the effectiveness of the bidirectional electron transfer channels in promoting charge carrier migration and suppressing charge carrier recombination for boosting photocatalytic hydrogen evolution and provides an efficient strategy for the actual application of g-C3N4-based photocatalysts.

Tailoring Ion Transport in Li3-3yHo1+yCl6-xBrx via Transition-Metal Free Structural Planes and Charge Carrier Distribution.

Localized atomistic disorder in halide-based solid electrolytes (SEs) can be leveraged to boost Li+ mobility. In this study, Li+ transport in structurally modified Li3HoCl6, via Br- introduction and Li+ deficiency, is explored. The optimized Li3-3 yHo1+ yCl6- xBrx achieves an ionic conductivity of 3.8 mS cm-1 at 25°C, the highest reported for holmium halide materials. 6,7Li nuclear magnetic resonance and relaxometry investigations unveil enhanced ion dynamics with bromination, attaining a Li+ motional rate neighboring 116 MHz. X-ray diffraction analyses reveal mixed-anion-induced phase transitions with disproportionate octahedral expansions and distortions, creating Ho-free planes with favorable energetics for Li+ migration. Bond valence site energy analysis highlights preferred Li+ transport pathways, particularly in structural planes devoid of Ho3+ blocking effects. Molecular dynamics simulations corroborate enhanced Li+ diffusion with Br- introduction into Li3HoCl6. Li-Ho electrostatic repulsions in the (001) plane presumably drive Li+ diffusion into the Ho-free (002) layer, enabling rapid intraplanar Li+ motion and exchange between the 2d and 4h sites. Li3-3 yHo1+ yCl6- xBrx also demonstrates good battery cycling stability. These findings offer valuable insights into the intricate correlations between structure and ion transport and will help guide the design of high-performance fast ion conductors for all-solid-state batteries.

Construction of 1D Molecular Conductive Wires Through a Polarized Gene Weaving Strategy for Efficient Electromagnetic Wave Absorption.

The growing threat of electromagnetic pollution has become a pressing safety concern. Metal-organic framework (MOF) derivatives are considered ideal candidates for mitigating electromagnetic radiation. However, due to the limitations imposed by complex post-processing and disruption of pristine crystal structures, the mechanisms of electromagnetic wave absorption remain unclear, let alone achieving atomic-level regulation in MOF derivatives. Moreover, research on MOF-based electromagnetic wave absorbers (EMWA) has predominantly focused on 2D and 3D structures, leaving 1D MOFs largely unexplored. To address these challenges, a bottom-up polarization gene weaving strategy is proposed to integrate polarizable conjugated groups, thieno(3,2-b)thiophene (TBTT), into two types of conductive MOFs by fine-tuning self-assembly conditions. As expected, both MOFs exhibited strong natural polarization effects. Among them, the 1D linear coordination mode of CuTBTT-1D demonstrated enhanced charge carrier mobility and geometric effects compared to the 2D structure, CuTBTT-2D. The synthesized 1D molecular polarization wire, with a thickness of 2.2mm, achieved ultra-high reflection loss (-77dB) and super-wide absorption bandwidth (6.52GHz). Its performance surpasses that of all known MOF-based EMWAs. This study provides a valuable strategy for the rational design of next-generation 1D MOF EMWA with atomic precision.

Biogas Purification by Methane and Acetate Manufacturing

ABSTRACTWastewater treatment plants have two persistent financial and energetic drains, the carbon dioxide content of biogas, which limits its commercial sale, and the presence of trace organics in the wastewater effluent, which damages the aquatic ecosystem, like the Great Barrier Reef. Biogas is a renewable methane resource that is underutilized due to the variable CO2 content (~40%). Biogas is energy intensive to purify and limited by the economy of scale (> 8.85 GJ/h) to large‐scale purification methods, thus small‐scale processes require development. Electrocatalytic microbes native to wastewater have been shown to convert CO2 to CH4 and acetate, however complete conversion of the CO2 content to CH4 is energy intensive. Here we show a low power bioelectrochemical fuel cell design to purify biogas to pipeline quality methane (98%), manufacture methane and/or acetate, and remove trace organics, using HCO3− as the transport charge carrier from dissolved CO2 from the biogas through an anion exchange membrane. This decreased the power required to separate CO2 from methane in biogas on a molar basis, resulting in a net energy recovery similar to current industrial systems. Magnesium anode use resulted in an energy positive system. Tests evaluated the influence of cathode potential on the current density, HCO3− ion flux and the rates and efficiencies of methane production, resulting in optimization at −0.7 V versus standard hydrogen electrode (SHE). A techno‐economic analysis modeled a positive return on investment for scaled‐up production to purify small biogas streams that are otherwise financially unrecoverable. Carbon sequestration by production of methane, acetate and solid fertilizers demonstrated profitable and energy efficient waste‐to‐resource conversion.

Tunneling Dielectric Thickness‐Dependent Behaviors in Transistors Based on Sandwiched Small Molecule and Insulating Layer Structures

AbstractThis work demonstrates the floating gate devices featuring a small molecule‐insulator‐small molecule‐insulator sandwiched structure, where the versatile electrical characteristics can be achieved depending on the thickness of the intermediate parylene tunneling dielectric layer (TDL). For the thin parylene layer of 15 nm (parallel DNTT channel transistor), channel also forms in the lower DNTT layer, allowing hole carriers to tunnel through the parylene TDL. The parallel DNTT channel transistor exhibits electrical characteristics similar to a conventional DNTT transistor with the increased contact resistance due to the presence of the intermediate parylene layer. When the parylene TDL is slightly thicker to be 45 nm, negative differential transconductance followed by current saturation behavior is observed, due to tunneling through the parylene TDL. Finally, photomemory is demonstrated with the sufficiently thick parylene layer (≈80 nm), where hole carriers injected from the electrode cannot tunnel through the parylene TDL, allowing the lower DNTT layer to act as a floating gate for the photogenerated charge carriers. This photomemory shows programmability under the light illumination with the specific wavelength as well as the robust retention and endurance characteristics. Furthermore, the photomemory has been successfully implemented on flexible paper substrates.

Effects of Interfacial Parameters and Temperature on Effective Schottky Barrier Height of Metal-Wrapped (Al-Gan) Nanowire Schottky Diode

Junction interface parameters (interface states density, interface layer thickness, interface permittivity and neutral surface states) and temperature effects have been studied. Results have shown that for the scaled structure doping functions below degeneracy state and temperature have significant impact on the effective Schottky barrier height while the interface parameters show no significant change. The barrier height has been observed to increase as the temperature increases almost linearly by ~5.171×10-3eV with increase in temperature from 300K to 420 K and this may be associated with the avalanched charge carriers being transported across the barrier height. The interface layer thickness in the range of 1.5 nm to 3.0 nm shows no effect on the carrier transport characteristics curves of the Schottky diode whereas the ideality factor has been found to decrease with an increase in temperature.

Design of MnOx/TiO2 Nanostructures for Photocatalytic Removal of 2,4-D Herbicide.

The research and modification of semiconductors through different synthesis routes allow obtaining materials with optimal properties to induce new energy levels and improve charge separation efficiency. In this context, the sol-gel method was used to synthesize TiO2-based materials doped with different percentages of MnOx to evaluate their photocatalytic activity in the degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in water under UV irradiation. Characterization results revealed a reduction in crystallite size to 7.2 nm. Adding MnOx enhanced the optical absorption of TiO2, resulting in a shift toward the red end of the spectrum of the forbidden energy band. The photocatalytic activity increased significantly with the percentage of MnOx, reaching a maximum degradation of 70 % in 6 hours with the 3 MnTi material. This increase was attributed to the synthesis method, which facilitated the formation of nanostructured heterojunctions mainly composed of TiO2 and MnO2, reducing the recombination of electron-hole pairs. TEM analysis confirmed these structures. A reaction mechanism for the 3 MnTi material is proposed, considering the mobility of charge carriers and the photooxidation processes of the pollutant.

Solution Processable Se-annulated Swallow Tail Perylene Bisimide Exhibiting Room Temperature Columnar Phase and Efficient Ambipolar Charge Carrier Mobility.

This study presents a selenium-annulated perylene bisimide (PBI-SeST) stabilizing room temperature columnar hexagonal phase with exceptionally low clearing temperature. The synthesis of this Se-annulated PBI (PBI-SeST) was accomplished using the reductive Cadogan cyclization method, with the introduction of swallow tails to reduce the clearing temperature and improve solubility. In addition, the charge carrier mobility of the Se-bay annulated PBI is assessed by space charge limited current (SCLC) technique and juxtaposed with PBI as well as nitrogen and sulphur-bay-annulated PBIs. It is noteworthy that all these PBIs exhibited ambipolar charge carrier mobility, a characteristic that diverges from the prevailing literature where predominantly electron transport behavior was observed for PBIs. This distinguishes them as an exclusive category of solution-processable, self-assembling organic semiconductors.

Catalyst-assisted growth of CsPbBr3 perovskite nanowires.

Halide perovskites (HPs), particularly at the nanoscale, attract attention due to their unique optical properties compared to other semiconductors. They exhibit bright emission, defect tolerance, and a broad tunable band gap. The ability to directly transport charge carriers along the HPs nanowires (NWs) has led to the development of methods for their synthesis. Most of these methods involve some version of an oriented attachment step with various modifications. In this study, we introduce CsPbBr3 nanowires produced via the solution-solid-solid (SSS) catalyst-assisted growth mechanism for the first time. We explored the kinetics of this process and examined the connection between the catalyst phase and its reactivity. We show how HP NWs grow with different SSS catalysts (i.e., Ag2S, Ag2Se, CuS) and discuss the required conditions for successful synthesis utilizing this mechanism. This method opens up a new avenue for producing HP NWs, which can be used to design and form new types of hybrid nanostructures.

Electrical Control of Electroluminescence in 2D Semiconductor Light Emitting Device through Synchronous Injection of Electrons and Holes

AbstractAchieving efficient electroluminescence (EL) in 2D materials requires precise control over the injection and recombination of charge carriers—electrons and holes. In this study, a method is introduced to improve charge carrier injection in using transition metal dichalcogenides (TMDCs) based light emitting devices driven by alternating current (AC), achieved through dual pulse injection. The dual pulse device exhibits a notable enhancement in EL intensity, displaying a substantial increase as compared to the single pulse device, achieving an approximate sixfold improvement. The proposed dual pulse operated device configuration enables the independent control of electron and hole injection, facilitating the fine‐tuning of carrier recombination processes to improve the EL emission efficiency. Phase delay dependent EL characteristics are observed featuring a maximum integrated EL at a phase delay of 180° indicating an enhanced EL emission during out‐of‐phase pulse operation between the electrodes. Moreover, the dual pulse device exhibited a ≈3.5‐fold improvement in the device EL external efficiency (ηe) when compared to the device operated with a single pulse. Manipulating carrier recombination in TMDCs‐based LEDs opens up new opportunities to enhance their performance, enabling practical applications in display technology, lighting, optical communication, and electrically tunable light sources.

Structural, electronic, vibrational, optical and thermoelectric properties of 1T-Na2O monolayer via MD and DFT study

Abstract Density Functional Theory (DFT) was implemented to determine the physical properties of the 1T-Na2O monolayer with the aid of WIEN2k software. To determine the electronic property exchange correlation such as GGA and hybrid functionals were implemented. The electronic property studies unveiled the 1T-Na2O monolayer as a direct bandgap semiconductor that has band gap values of 1.68 eV and 2.75 eV with GGA and hybrid correlation functionals. The dynamical stability of the 1T-Na2O monolayer was established by harnessing Phonon dispersion analysis, while the thermal stability was established by harnessing the Ab-initio Molecular Dynamics (AIMD). The optical properties investigation revealed that the 1T-Na2O monolayer shows an excellent absorption coefficient in the UV region and has a potential application in optoelectronic applications. The 1T-Na2O monolayer shows promise for waste heat recovery systems due to its thermoelectric properties, with a figure of merit of 0.82 at 400 K. The effective masses of electrons and holes (charge carriers) are determined. The relative ratio was estimated to determine the recombination rate of charge carriers and was found to be limited.

Chemical Synthesis of ~1 nm Multilevel Capacitor‐like Particles with Atomic Precision

AbstractCan the chemically synthesized nanoparticles act as nanodevices or nanomachines? Herein, we demonstrated this feasibility. A novel nanocluster (ultrasmall nanoparticle) [Au44Cd20(m‐MBT)40][N(C8H17)4]2 (Au44Cd20 in short, m‐MBTH: m‐methylbenzenethiol) obtained via developing a synthesis method has a cannula‐like structure of the outer shell and an internal sleeve, revealed by single‐crystal X‐ray diffraction. Natural population analysis (NPA) charge calculations, charge carrier transport of Au44Cd20 (during which an intra‐nanocluster anti‐galvanic reaction was observed) after unneutral charging using NaBH4 as well as voltammetry proved the capacitor‐like character of Au44Cd20. The subsidiary capacitor‐like character of the outer shell of Au44Cd20 was further probed via NPA charge calculations and electrocatalytic reduction of CO2 to CO. Thus, this study predicts a new era of engineering metal nanoparticles for realizing atomically precise ultrasmall nanodevices and nanomachines.

SYNTHESIS AND OPTICAL PROPERTIES OF POLYCRYSTALLINE Sb2S3 AND (Sb2S3)90Ag10

Recently, much research has been devoted to finding new or improving existing photovoltaic materials. P-metal chalcogenides are attracting increasing attention due to their unique properties, including high photon absorption coefficient, significant dipole moment, optimal band gap and the ability to form solid solutions. To optimize the electrical parameters (band gap, concentration of charge carriers) in order to improve the performance of solar cells, the formation of doped compounds is used. In the present work, the synthesis and study of silver-doped polycrystalline Sb2S3 was carried out. The obtained alloys were characterized by X-ray diffraction and diffuse reflectance spectroscopy. The phase composition of the synthesized alloys was determined by X-ray diffraction method. The powder patterns of the (Sb2S3)90Ag10 alloy contains two systems of reflexes: those corresponding to the Sb2S3 and ternary AgSbS2 phases. The optical parameters of the synthesized materials were studied by diffuse reflectance spectroscopy method. The diffuse reflectance spectra were analyzed using the Kubelka-Munk function. The pseudogap was determined using the Tauc method.