Sn-doped ZnO Research Articles

Sn-Doped Zinc Oxide as an Electron Transporting Layer for Enhanced Performance in PbS Quantum Dot Solar Cells.

Colloidal PbS quantum dot solar cells (QDSCs) have been primarily demonstrated in n-i-p structures by incorporating a solution-processed ZnO electron transporting layer (ETL). Nevertheless, the inherent energy barrier for the electron extraction at the ZnO/PbS junction along with the defective nature significantly diminishes the performance of the PbS QDSCs. In this study, by employing Sn-doped ZnO (ZTO) ETL, we have tuned the conduction band offset at the junction from spike-type to cliff-type so that the electron extraction barrier can be eliminated and the overall photovoltaic parameters can be enhanced (open-circuit voltage of 0.7 V, fill factor over 70%, and efficiency of 11.3%) as compared with the counterpart with the undoped ZnO ETL. The X-ray photoelectron spectroscopy (XPS) analysis revealed a mitigation of oxygen vacancies in the ZTO ETL of our PbS QDSCs. Our work signifies the importance of Sn doping into the conventional ZnO ETL for the superior electron extraction in PbS QDSCs.

ZnO/ITO, Sn and Cu Doped ZnO/ITO Films as an Photoanode for Solar Cell: Production and Characterizations

Undoped ZnO and Sn- and Cu-doped ZnO thin films were fabricated on ITO substrates via the SILAR method for this study. The films were then subjected to structural, surface, optical, and electrical characterization. The undoped ZnO thin films displayed a spherical surface morphology, while the Sn-doped ZnO thin films exhibited a nano-flower surface morphology. On the other hand, the Cu-doped ZnO thin films demonstrated a relatively thicker and flat layer, as well as a fractured surface morphology that resulted in voids. The level of crystallization and transmittance values augmented upon doping. With Cu doping, n-p heterojunction structure was obtained from ZnO/ITO films. Hence, it is inferred that the generated Cu doped ZnO/ITO films can serve as alternative transparent conductive films (TCO) due to their low resistivity.

Dual effect to improve the electrical properties of SZO films grown by nitrogen pneumatic spray pyrolysis.

The principal aim of this study is to reduce considerably, via Sn doping, the resistivity of ZnO thin films prepared by simple, flexible, and cost-effective nitrogen pneumatic spray pyrolysis (NPSP) method on glass substrates at a temperature of 400°C. Different Sn content was tested (Sn/Zn = 0, 1, 3, 5 wt%) in an attempt to reduce the concentration of excessive oxygen atoms and create more free electrons. The microstructural, optical, morphological, and electrical properties of the films have been studied. The x-ray diffraction analysis demonstrated that tin-doped SZO films exhibited polycrystalline nature with a preferential orientation along (002) plane with the appearance of a new orientation (101) with the increase of Sn concentration leading then to bidirectional growth. The deposited SZO films showed an average optical transmittance of about 80% in the UV-visible region (200-800 nm) with optical band gap values at around 3.27 eV. Photoluminescence emissions of SZO samples presented three main peaks: near band edge emission, violet emission, and the blue-green emission. The surface morphology of the films obtained by scanning electron microscope (SEM) exhibited the change in morphology with increasing the Sn content. A minimum electrical resistivity value of about 17·10-3 Ω·cm was obtained for 3% SZO films. SZO films prepared by the NPSP method can be used as transparent window layer and electrodes in solar cells. RESEARCH HIGHLIGHTS: Highly oriented, conducting, and transparent Sn-doped ZnO films are successfully synthesized. The film growth orientation changed from mono-directional (002) axis to bi-directional (002) and (101) axis according to Sn doping. Ultraviolet and green emissions are noted by photoluminescence investigation. A minimum resistivity is observed for 3 wt% SZO film. The dual positive effect of the carrier gas used (N2) and Sn doping is confirmed.

Effect of tin concentrations on the elemental and optical properties of zinc oxide thin films

Pure zinc oxide and Sn-doped ZnO thin films were deposited on a pre-heated glass substrate from tin (II) chloride dihydrate (SnCl2.2H2O) and zinc acetate (Zn(CH3COO))2 precursors using spray pyrolysis technique. The doped films were achieved by adding various quantities of (SnCl2. 2H2O) precursor to the solution of zinc acetate in volume percent range of 0–10. Rutherford Backscattering Spectrometry (RBS) was used to characterise the prepared films to determine their thickness and elemental composition. To examine the films' optical characteristics, a UV spectrometer operating at room temperature and covering a wavelength range of 300–1100 nm was employed. The film's thickness and composition show that as the volume of Sn in the thin films increases, so does the film's thickness. With average transmittance values up to 70 %, all the films are quite transparent in the visible region of the electromagnetic spectrum and have a significant UV cut-off at roughly 380 nm. The reflectivity of Sn-doped ZnO films is seen to be independent of the volume of Sn in the films, and the reflectivity of the films diminishes as the wavelength increases. Sn-doped ZnO thin film has an optical band gap of 3.14–3.18 eV. The properties of the thin film produced make it suitable for solar energy collection and improve the efficiency of solar energy system, various optoelectronics devices and sensor.

Harnessing the Power of Sn-Doped ZnO Rice-Shaped Nanomaterials for Microbial Defense

Hydrothermally synthesized Sn-doped ZnO nanorices underwent comprehensive characterization, encompassing structural, morphological, compositional, optical, and vibrational features using advanced techniques. Field Emission Scanning Electron Microscopy (FESEM) revealed nanorices with dimensions 0.5—0.9 μm length and 80—150 nm width and distinctive morphology, displaying tapered or pointed ends, flower-like agglomeration, and a textured surface. X-ray Diffraction (XRD) confirmed the wurtzite hexagonal phase, and the Debye-Scherer equation estimated an average crystal size of 9.17 nm. Antibacterial assessment against Bacillus cereus exhibited a notable dose-dependent effect, with substantial zones of inhibition (ZOI) at 90 μg/mL, comparable to standard antibiotics like Ciprofloxacin. Antifungal evaluation against Candida albicans demonstrated a dosedependent trend, indicating a potent hindrance of fungal growth at higher concentrations. Comparative analysis against the standard antifungal agent, Itraconazole, revealed a marginally superior antimicrobial effect of Sn-doped ZnO nanorices at the highest concentration tested. The nanorices exhibited comparable or superior efficacy compared to standard drugs, highlighting their potential as effective and tailored antimicrobial agents.

Structural, morphological and optical properties of Sn doped zinc oxide thin films synthesis by sol-gel method for photocatalytic applications

Undoped and tin (Sn)-doped ZnO thin films were synthesized via sol-gel technique and deposited onto the glass substrates using the spin-coating technique. The impact of Sn incorporation at various concentrations on the structural, morphological, and optical properties of ZnO films was studied x-ray diffraction revealed a hexagonal crystal structure for all samples with a preferential crystalline orientation along the (002) plane. The transparency of Sn-doped ZnO thin film in the visible region significantly increased from 75% to 90%. The morphological analysis revealed a decrease in the grain size from 21 nm to 15 nm with Sn content in the matrix of ZnO. The optical properties reveal the contribution of the Burstein-Moss effect and electron-impurity scattering to slightly widen the bandgap from 3.22 eV to 3.24 eV. Urbach energy values demonstrated that the presence of Sn dopant increased the tail-band width of the localized states. These observations suggest that the deposited Sn-ZnO thin films could have possible applications as a photocatalyst for methylene blue (MB) dye degradation.

Sn-doped ZnO for efficient and stable quantum dot light-emitting diodes via a microchannel synthesis strategy.

ZnO nanocrystals (NCs) are widely employed as an electron transport layer (ETL) in quantum-dot light-emitting diodes (QLEDs). However, the excessive electron mobility, abundant surface defects and poor reproducibility of ZnO NC synthesis are currently the primary restrictive factors influencing the development of QLEDs. In this study, we developed Sn(IV)-doped ZnO NCs as the ETL for constructing highly efficient and long lifetime QLEDs. The introduction of Sn can reduce the surface hydroxyl oxygen defects and alter the electron transport properties of NCs, and thus is beneficial for improving the efficiency of hole-electron recombination in the emitting layer. Meanwhile, a microchannel (MC) reactor is utilized to finely control the synthesis of Zn0.96Sn0.04O NCs, enabling us to achieve uniform size distribution and consistent production reproducibility. Using the Sn(IV)-doped ZnO NCs as the ETL has led to a remarkable enhancement of external quantum efficiency (EQE) for the fabricated red QLED, from 9.2% of the ZnO only device to 15.5% of the Zn0.96Sn0.04O device. Furthermore, the T70 (@1000 cd m-2) of the Zn0.96Sn0.04O device reached 78 h, which is 1.77-fold higher than that of the ZnO only device (44 h). The present work provides an alternative ETL for efficient and stable QLEDs.

Structural and photoelectric properties of Sn-doped ZnO thin film with the co-sputtering method

Sn-doped ZnO thin films have been prepared with magnetron co-sputtering. The results indicate that this method can improve the micro-structure of films and enhance its photoelectric performance. The structure and surface morphology results indicate that all the doped films show the preferred orientation (0 0 2), the roughness can decrease to 1.81 nm at 15 W with increasing DC power, the carrier concentration, resistivity decreases, and mobility can reach 7.99×1019 cm−3, 1.27×10−4 Ω·cm and 1047.5 cm2/Vs, respectively, and the observed optical band gap can increase to increase to 3.85 eV.

Adsorption of NH3 and NO2 Molecules on Sn-Doped and Undoped ZnO (101) Surfaces Using Density Functional Theory

The adsorption and interaction mechanisms of gaseous molecules on ZnO surfaces have received considerable attention because of their technological applications in gas sensing. The adsorption behavior of NH3 and NO2 molecules on undoped and Sn-doped ZnO (101) surfaces was investigated using density functional theory. The current findings revealed that both molecules adsorb via chemisorption rather than physisorption, with all the adsorption energy values found to be negative. The calculated adsorption energy revealed that the adsorption of the NH3 molecule on the bare ZnO surface is more energetically favorable than the adsorption of the NO2 molecule. However, a stable adsorption configuration was discovered for the NO2 molecule on the surface of the Sn-doped ZnO surface. Furthermore, the adsorption on the undoped surface increased the work function, while the adsorption on the doped surface decreased. The charge density redistribution showed charge accumulation and depletion on both adsorbent and adsorbate. In addition, the density of states and band structures were studied to investigate the electronic behavior of NH3 and NO2 molecules adsorbed on undoped and Sn-doped ZnO (101) surfaces.

Synthesis of Sn-doped ZnO catalysts by solution combustion method for photocatalytic activity: a parametric study

Synthesis of Sn-doped ZnO catalysts by solution combustion method for photocatalytic activity: a parametric study

Effect of doping and loading Parameters on photocatalytic degradation of brilliant green using Sn doped ZnO loaded CSAC

Sn doped ZnO loaded cotton stalk activated carbon (Sn–ZnO/CSAC) was prepared by chemical precipitation method, and the products were characterized. The XRD resultants confirm that the presence of hexagonal wurtzite phase of the bare ZnO. Furthermore, particular particle size gradually decreases (21.49 nm) due to doping and loading. UV–Vis absorption intensity of doped/loaded sample was red-shifted and then PL intensity is reduced. The photocatalytic performances of bare, Sn-doped ZnO and Sn–ZnO/CSAC was estimated by photodegradation of brilliant green (BG) under sunlight. The photodegradation of BG dye in 120 min over Sn-doped ZnO/CSAC is nearly 96.52%, which is considerably improved than bare ZnO (72.60%), respectively.

Label-free photoelectrochemical immunosensor based on sensitive photocatalytic surface of Sn doped ZnO for detection of hepatitis C (HCV) anticore mAbs 19D9D6

Photoelectrochemical (PEC) based immunosensors are important bioanalytical tools for the label free detection of hepatitis C (HCV) antibodies as the photocurrent in the external circuit which is the response signal is not effected intrinsically by the excitation stimulus of light. Therefore, in this article, the facile development of label-free photoelectrochemical (PEC) immunosensor for the detection of hepatitis C (HCV) anticore mAbs 19D9D6 (1 NLB monoclonal antibodies) is reported. The photoactive ZnO was applied as matrix which was further doped with Sn in order to enhance the PEC properties for constructing the PEC immunosensor through immobilization of truncated recombinant HCV core nucleocapsid polypeptide antigen (residues 13–40) corresponding to immunodominant region as biolayer for immunospecific interaction. Morphological analysis was carried out using Scanning electron microscopy (SEM). X-ray diffraction (XRD) was performed for the structural analysis of the pure ZnO and Sn doped ZnO matrix. Optical properties were evaluated using the UV–visible spectroscopy that was further used to attain Mott–Schottky plot, Tauc plot and Urbach plot that explained in detail the PEC enhancement in terms of the energy band gap ( E g ). The results depicted a significant red shift in the light absorption by Sn-doped ZnO electrode due to band shrinkage. Defect sites induced due to doping also hinders the photo-generated electron-hole pair recombination. Consequently, the photocurrent density of Sn doped ZnO electrode increased approximately two fold when subjected to illumination. The insulative layer formation at the semi-conductor solution junction resulted in a significant decrease in the photocurrent density that was successfully applied to monitor the immunospecific interaction between the antigen and antibody. PEC immunosensor has the linear detection range from 0.006 to 60 ng mL -1 anticore mAbs 19D9D6 (1 NLB monoclonal antibodies) concentration with 0.53 pg mL -1 (S/N = 3) detection limit as a function of photocurrent decrement which is low for enhancing the sensitivity to effectively measure the antibody. The as prepared PEC immunosensor displayed high selectivity and stability due to which it can be rendered as capable photoelectrochemical scheme for protein detection in the point of care medical diagnosis.

Impact of Sn doping on the hydrogen detection characteristics of ZnO thin films: Insights from experimental and DFT combination

The development of efficient chemical sensors based on semiconductor oxides is a major challenge. Low-cost equipment fabrication with a high sensor response towards H2 was the aim of our work. Chemical sensors were elaborated using zinc oxide, aluminum- and tin-doped zinc oxide. The samples were synthesized with a cost-effective chemical spray pyrolysis technique. Sn-doped ZnO response to hydrogen gas is the highest followed by ZnO and Al-doped ZnO, with a high sensitivity reaching 200 at 500 ppm, for 400 °C. DFT calculations revealed that O2 is strongly adsorbed on the ZnO-Al surface, resulting in the cancellation of the electrical conductance. Consequently, the approaching H2 gas will not possess sufficient energy to extract the strongly adsorbed oxygen from the surface, and no trapped electrons can be released back to the surface. In contrast, DFT calculations highlighted the potential of ZnO and Sn-doped ZnO to be used as hydrogen gas sensors. Charge transfer analysis revealed that only a small release of the trapped electrons occurs on the pure ZnO surface (0.14|e|), compared to Sn doped ZnO, in which a full release of free electrons was observed, resulting in a more favorable response to H2 and confirming the experimental results.

Low-temperature processable Sn-doped ZnO films as electron transporting layers for perovskite solar cells

Low-temperature processable Sn-doped ZnO films as electron transporting layers for perovskite solar cells

Optical Properties of Sn Doped ZnO Thin Film Prepared Using Sol-Gel Method for Optical Limiting Application

In this work, pure Zinc oxide and tin doped Zinc oxide thin films nanoparticles with various volume concentrations of 2, 4, 6, and 8V/V% were prepared by using the sol-gel method. The optical properties were investigated by using UV-Visible spectroscope, and the value exhibits the direct allowed transition. The average of transmittance was around ~(17-23) %in visible region. The optical energy band gap was calculated with wavelength (300-900) nm for pure ZnO and Sn doped ZnO thin films which decreases with increasing concentration from 3.4 eV to 3.1 eV respectively and red shift. The real dielectric(εr) and the imaginary dielectric εiare the same behavior of the refractive index(n) the extinction coefficient (k) respectively. The optical limiting properties were studied by using an SDL laser with a wavelength of 235 nm. ZnO and doping thin films an found efficient as optic limiting and depend on the concentration of the all samples.

Effect of glutathione capping on the antibacterial activity of tin doped ZnO nanoparticles

In the present study, we first synthesized pristine ZnO and Sn doped ZnO nanoparticles (NPs) then capped the synthesized NPs by Glutathione at different capping concentrations. The structural, morphological, and optical properties of synthesized NPs was examined by x-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), UV–visible, and energy resolved photoluminescence spectroscopy. The XRD analysis confirmed the formation of wurtzite crystal structure of ZnO nano-crystallites while TEM micrographs showed the formation of dendrite nanostructure at higher capping concentration of glutathione in Sn doped ZnO NPS. Strong absorption band around 2525 cm−1 in the IR spectrum indicates the presence of S–H stretching vibration of glutathione which has been disappeared in glutathione capped ZnO NPs. Blue shift in absorption edge was observed in glutathione capped ZnO NPs as compared to uncapped NPs. Moreover, the synthesized NPs showed excellent response against both Gram positive bacteria (Streptococcus sp. & Staphylococcus sp.) and Gram negative (E. coli & Klebsiella sp.) bacteria. Maximum zone of inhibition has been observed with glutathione capped Sn doped ZnO nanostructures. Hence, it can be concluded from the present investigation that the optimization of capping concentration will be very beneficial to exploit Sn doped ZnO semiconductor nanostructures as a coating material for different chemotherapeutic drugs.

Photocatalytic activity of Sn-doped ZnO synthesized via peroxide route

ZnO*ZnO2 mixture was prepared by thermal hydrolysis of a zinc peroxo-complex precursor in presence of Sn2+ and Sn4+ ions. The effect of different tin valence states on structure and photocatalytic properties of the resulting products was investigated. All samples before annealing contained ZnO2 and except one sample also SnO2. Microstructural analysis showed a difference in morphology between the two sets of samples. A difference was also observed for the specific surface area. The photocatalytic decolorization of Orange II dye was employed to determine the photocatalytic activity of the samples; Sn2+ doped samples were more active than Sn4+ doped ZnO samples. Temperature 600 °C was optimal for annealing - the sample ZnP150Sn2 annealed at 600 °C had the highest rate constant (0.0730 min−1) among the samples. Additional increase of Sn2+ amount led to further increase in rate constant (0.0937 min−1 for the sample ZnP200Sn2) up to a certain point.

Preparation of a stable polyurethane sponge supported Sn-doped ZnO composite via double-template-regulated bionic mineralization for visible-light-driven photocatalytic degradation of tetracycline

A new tin-doped zinc oxide@polydopamine-modified polyurethane (Sn-ZnO@PDA/PU) composite photocatalyst was prepared by in-situ growth of tin-doped zinc oxide (Sn-ZnO) on the surface of polydopamine-modified polyurethane (PDA/PU) via double-template-regulated bionic mineralization strategy. The flake-like Sn-ZnO regulated by soft template (sodium citrate) contributed to outstanding photocatalytic activity of Sn-ZnO@PDA/PU composite. In addition, the intimate interface and stable structure between Sn-ZnO and PDA/PU promoted by double-template-regulated bionic mineralization induced the formation of more active sites and extended absorption from UV to visible region. In the visible-light-driven reaction for the degradation of tetracycline (TC) using Sn-ZnO@PDA/PU as photocatalyst, 96.8% of TC removal and 42.3% of TOC removal were achieved within 120 min under optimal reaction conditions. The removal rates of TC were all more than 90% in a wide pH range of 4–11. Sn-ZnO@PDA/PU showed a promising cycling stability, which kept high-efficiency TC removal of 91.7% and low leaching rate of zinc after five cycles. This was ascribed to that the special morphologic structure of the composite could accelerate charge transfer and reduce the defect exposure, thereby protecting Sn-ZnO from photo-corrosion and environmental implication during photocatalyst reaction. Comprehensive and comparative studies indicated that the Sn-ZnO@PDA/PU composite exhibited outstanding photocatalytic activity, reusability, and stability, which has great application potential for efficient degradation of organic contaminants in wastewater.

A Composite Material of Hydrothermal Prepared Blue Fescue-Like CQDs/Sn-Doped ZnO with Enhanced Visible Light-Driven Photocatalytic Activity

Novel Blue Fescue-like CQDs/Sn-doped ZnO composite photocatalyst was successfully synthesized via a gentle hydrothermal method. The hierarchical CQD/Sn-doped ZnO samples are assembled by many hexagonal prism-shaped nanoneedles. In addition, the photocatalytic performance of all samples was obtained by degrading rhodamine B(RhB) under visible light irradiation. The degradation results indicate that the photocatalytic activity of CQDs/Sn-doped ZnO is better than Sn-doped ZnO, CQDs/ZnO, pure CQDs and pure ZnO. The stability and reusability of CQDs/Sn-doped ZnO were confirmed by cyclic degradation experiments. It can be considered that the effective photocatalytic performance is attributed to the adsorption and transfer of electrons by CQDs.

Enhanced solar-light-driven photocatalytic activity of surfactant-assisted Sn4+-doped ZnO

The suggested work concentrates on preparing ZnO and the surfactant sodium hexametaphosphate (SHMP)-assisted pure and Sn4+-doped ZnO photocatalysts to degrade the organic dye methyl orange (MO). For that, a low-temperature hydrothermal technique was employed. For preparing the surfactant-assisted Sn-doped ZnO photocatalyst, varied levels (5, 10 and 15 mM) of Sn4+ ions have been employed. The prepared products were investigated for their structural, optical and morphological properties. The results of structural analysis reveal the hexagonal wurtzite phase of ZnO. The band gap of ZnO estimated using Kubelka–Munk function revealed a reduction from 3.34 to 3.28 eV on 5 mM of Sn4+ doping and then stepped up as the concentration of doping increases. The photocatalytic response of the catalysts was analysed to degrade the organic dye methyl orange (MO) under solar light irradiation. The surfactant-assisted ZnO doped with 5 mM of Sn4+ ions displayed better performance (90%) than the ZnO (76%) and the surfactant-assisted ZnO (80%) in MO degradation.