Annealing Of Films Research Articles

Enhanced Impact Resistance, Oxygen Barrier, and Thermal Dimensional Stability of Biaxially Processed Miscible Poly(Lactic Acid)/Poly(Butylene Succinate) Thin Films

This study investigates the crystallization, microstructure, and performance of poly(lactic acid)/poly(butylene succinate) (PLA/PBS) thin films processed through blown film extrusion and biaxial orientation (BO) at various blend ratios. Succinic anhydride (SA) was used to enhance interfacial adhesion in PLA-rich blends, while blends near 50/50 formed co-continuous phases without SA. Biaxial stretching and annealing, adjusted according to the crystallization behavior of PLA and PBS, significantly influenced crystallinity, crystallite size, and molecular orientation. Biaxial stretching induced crystallization and ordered chain alignment, particularly at the cold crystallization temperature (Tcc), leading to a 70–80-fold increase in impact resistance compared to blown films. Annealing further enhanced crystallinity, especially at the Tcc of PLA, resulting in larger crystallite sizes. BO films demonstrated reduced thermal shrinkage due to improved PLA crystalline structure, whereas PLA-rich blown films showed higher shrinkage due to PLA’s lower thermal resistance. The SA-miscibilized phase reduced oxygen transmission in blown films, while BO films exhibited higher permeability due to anisotropic crystal orientation. However, the annealing of BO films, especially at high temperature (Tcc of PLA), further lowered oxygen permeability by promoting the crystallization of both PLA and PBS phases. Overall, the combination of SA compatibilization, biaxial stretching, and annealing resulted in substantial improvements in mechanical strength, dimensional stability, and oxygen barrier properties, highlighting the potential of these films for packaging applications.

Improving the photoswitching performance of a transistor with amorphous metal oxide semiconductor thin film by a gradient annealing approach

Metal oxides are attracting attention as electronic mate rials in research and industry. Thin films of amorphous indium gallium zinc oxide (a-IGZO) exhibit low absorbance in the visible spectrum, making them ideal components in transparent electronics. To widen the scope of use for thin film transistor (TFT) devices based on a-IGZO in on-chip sensing applications, photoresponsive behavior has been achieved by proper engineering of the active layers by either introducing a photosensitive top layer or using a method to generate localized states inside the band gap. In this paper, we propose a bilayer structured with the use of thermal annealing of a-IGZO film at different temperatures. Thermal annealing has been shown to improve the electrical performance of the TFT devices because of the improved film quality but negatively affects the photoresponsivity by removing tarp sites that play an important role in both charge generation and photomultiplication via the photogating effect. Therefore, here we propose an a-IGZO film with a high temperature-annealed bottom layer and pristine top layer. The bottom layer plays a vital role in the charge transport behavior, resulting in a low threshold voltage and subthreshold swing similar to the device with a fully annealed film, while the photoresponse of the device is driven by the higher density of gap states in the pristine top layer. This proposed method is advantageous to previously published procedures due to the simplicity of using no additional materials and complex steps to introduce trap sites into the photoactive layer, but only differential annealing temperature.

Exploring Platinum Thin Films as Electrodes for High‐Temperature and ‐Pressure Electrochemical Studies in Aqueous Systems

ABSTRACTThis work reports a methodology for the fabrication of Pt thin‐film electrodes for electrochemical studies in hydrothermal systems. The research process was meticulous, with particular attention paid to the multilayer Ti/Pt/Ti/Al2O3 film structure and annealing conditions that are expected to impact the morphology of the films, surface composition and electrochemical response. The findings of this study are significant, as they provide valuable insights into the behaviour of Pt thin‐film electrodes in various media and conditions. Two different approaches were adopted for the preparation of the electrodes: in one case, the Ti/Pt/Ti/Al2O3 films deposited on sapphire wafers were exposed to rapid thermal annealing at 900°C under argon for 5 min, followed by argon ion milling to etch the final electrode pattern (Pt‐RA(900)), while in the other case, uncapped Pt films were annealed, after etching, in a tubular oven under argon at specific temperatures between 200°C and 900°C (Pt‐TO). Rapid annealing at 900°C on capped films resulted in the formation of a Pt3Ti intermetallic alloy with remarkable mechanical and chemical stability even after 10 h of immersion in deionised water, acid (0.1 M H2SO4) and alkaline media (0.1 M KOH) conditions at temperatures up to 150°C, despite the dissolution of the Al2O3 top layer at 150°C and long immersion times (> 10 h). In the case of uncapped Pt films, diffusion and oxidation of Ti through the Pt film at high temperature resulted in the formation of TiO2 on the surface of Pt. The results were confirmed by using a comprehensive suite of ex‐situ characterisation techniques to follow changes in the Pt electrode surface morphology and composition before and after immersion in H2O, 0.1 M H2SO4 and 0.1 M KOH solutions under argon. Ex‐situ electrochemical characterisation studies were also conducted to correlate the changes in the electrode surface properties, including the electrochemical surface area, with different annealing conditions and after various hydrothermal treatments in neutral, alkaline and acidic media.

Preparation and Characterization of Nanostructured ITO Thin Films by Spray Pyrolysis Technique: Dependence on Annealing Temperature

Transparent conducting oxides (TCOs) like Indium tin oxide (ITO) have wide attention from all scientists which have low resistance and high visible light transmittance, used as transparent electrodes in many optoelectronic devices such as liquid crystal displays, touch screens, light emitting diodes, and solar cells. In this research, the relationship between the crystallization, optical transmittance, and surface roughness of nanostructured ITO thin films and the change in annealing temperature was investigated. To enhance the efficiency of this material in optoelectronic applications, both the optical transmittance in the visible region and the crystallite size must be increased. These results can be obtained by the heat treatment of the films. Nanostructured ITO thin layer films have been successfully prepared at a substrate temperature equal to (350)℃ by chemical spray pyrolysis (CSP) technique. The physical characterizations of nanostructured ITO thin layer films were investigated at different annealing temperatures (400,450 and 500)℃. The presence of diffraction peaks indicates that the as-deposited and post annealed films are polycrystalline cubic structure and the peak (400) is a preferred growth orientation. For all samples the value of intensity of diffraction peaks increases with increasing substrate temperature. The crystallite size of nanostructured ITO thin films is strongly related to the annealing temperature. The crystallite size estimated from XRD was found to rise with rising annealing temperature. The surface roughness of nanostructured ITO thin layer films increases with rising annealing temperature. High values of transmittance have been measured in the visible region 550 nm equal to (70, 82, 84 and 88)% corresponding to annealing temperature (350,400,450 and 500)℃ respectively.

Enhancement of carrier concentration in chemical bath deposited copper sulfide (CuxS) thin film by post-growth annealing treatment

Copper sulfide thin films (CuxS, 1 ≤ x ≤ 2), owing to their unique optical and electrical properties, have attracted enormous attention in recent research. As one of the chalcogenide semiconductors, CuxS is used in several applications such as chemical sensors, photo-absorbing layers, photovoltaics, and lithium-ion batteries. In this study, copper sulfide thin film (CuxS; where 1 ≤ x ≤ 2) has been deposited by the chemical bath deposition method (CBD) at 27 °C with the molar ratio for copper and sulfur as 1:5, respectively. The structural, compositional, morphological, optical, and electrical properties of as-deposited and annealed CuxS thin films are investigated. From XRD plots, the presence of a mixture of two co-existing polycrystalline phases is observed, i. e. covellite phase with CuS stoichiometry and digenite phase with Cu1.8S stoichiometry up to an annealing temperature of 200 °C. At higher annealing temperatures, i.e. at 300 °C and 400 °C, the phase of CuxS thin film gets completely converted to digenite phase with Cu1.8S stoichiometry and chalcocite phase with Cu2S stoichiometry respectively. There is an enhancement in the crystallinity of CuxS thin film with an increase in annealing temperature as confirmed by XRD and Raman results. The optical bandgap of CuxS thin film is found to be decreased from 2.81 eV to 1.66 eV with an increase in the annealing temperature. The CuxS thin films are found to be p-type in nature, and the film annealed at 400 °C possesses the highest carrier concentration as revealed from the Hall effect measurement. This study aims to investigate the improvement of electrical properties of CuxS thin film with the variation in annealing temperature for optoelectronic applications such as photodetector.

Characterization and linear / nonlinear optical aspects of polyaniline (PANI) films incorporated with Ethylenediamine for low-cost limiting optical technologies

Polymer composite combined film with Polyaniline (PANI) and Ethylenediamine (EDA) were successfully synthesized via the spin coating technique on a glass substrate followed by different thermal annealing degrees and times. Successful incorporation of EDA into the PANI polymer matrix and the effect of the annealing temperature have been demonstrated by XRD, FTIR, FESEM and TEM. Using UV–Vis optical spectroscopy, we determine the absorption coefficient, band edge, and Urbach energy. The effects of different annealing temperatures and times on linear/nonlinear optical characteristics were investigated. The band gap of EDA-doped PANI films is reduced with the different thermal annealing from 3.43 eV to 3.19 eV, while the Urbach tail of the 100 °C/4h film which is 0.492 eV was decreased to 0.469 eV for 150 °C/1h sample. However, the absorbance and optical conductivity were both increased. Besides, the optical limiting effect assesses their potential to mitigate intense light. It was found from the study that for green wavelength 100 °C/4h film decreases the input power by 16.5 % whereas the 150 °C/1h sample shows superior limiting behavior of 99.96 %. It has been found that thermal annealing of the EDA-doped PANI films enhances the synthetic composite's optical characteristics, making the 150 °C/1h sample of EDA-doped PANI films appropriate for utilization in both energy applications and optoelectronics.

Third-order non-linear optical switching and threshold limiting of NiO thin films

This study discusses the nonlinear optical properties of as-grown and annealed NiO thin films using the Z-scan technique utilizing the femtosecond laser pulses at a repetition rate of 100 kHz of wavelength 1030 nm with a pulse duration of 370 fs. In open aperture measurements, pristine reveal saturable absorption (SA) with a negative sign of nonlinearity, while annealed samples exhibit reverse saturable absorption (RSA) with a positive sign of nonlinearity. In closed aperture conditions, all samples show prefocal minima and postfocal maxima, indicating self-focusing behavior. The observed RSA phenomena are attributed to the indirect two-photon absorption (TPA) process. The influence of surface plasmon resonance on nonlinear absorption is successfully ruled out due to insufficient excitation energy (1.20 eV) to induce resonance in the samples. The increase in bandgap with annealing temperature, associated with indirect TPA, is elucidated with the shifting of Ni-dx2-y2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$d_{x^2-y^2}$$\\end{document} and Ni-dz2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$d_{z^2}$$\\end{document} orbitals in the conduction band, under the framework of Density Functional Theory (DFT). The DFT results are correlated with the observed nonlinear SA and RSA processes. The Ni d-d and Ni-d to O-p transitions contribute to the modulation of nonlinearity in the indirect TPA process. The study suggests that the sample annealed at 400 °C exhibits superior optical limiting properties with the highest nonlinear absorption coefficients compared to the other annealed sample, while the as-grown sample is suitable for passive Q-switching applications.

Comprehensive analysis of chemical composition, electronic, luminescent, and electrical properties of amorphous graphite-silicon carbide thin films: A comparative study of as-deposited and post-annealed states

Graphite/SiC (GSC) thin films were synthesized on silicon substrates via a spray method, depositing a Si-graphite solution on preheated silicon samples at 350 °C, followed by annealing at 800 °C for 4 h. A systematic approach was employed to ensure the effective incorporation of graphite into the SiC material during solution preparation. Various analytical techniques, including XPS, UPS, Reflection Energy Electron Loss Spectroscopy (REELS), PL, AFM, and Hall effect measurements, were employed for comparative analysis of the chemical composition, morphological, electrical, and optoelectronic properties of as-deposited and annealed GSC films. XPS analysis revealed the presence of Si—C and graphitic bonds in the as-deposited GSC, with a significant compositional shift to oxygen-rich graphite oxide/oxycarbides after annealing. REELS demonstrated increased bandgap and bulk plasmon energy due to surface oxidation, while UPS highlighted a high electronic density in the as-deposited film, diminishing after annealing. AFM revealed a tendency of as-deposited GSC grains to form smaller, sharper structures after annealing, resulting in smoother and more homogeneous surface morphology. Phase AFM confirmed graphite incorporation at grain boundaries and within the bulk, forming a composite structure. PL spectra of the as-deposited film exhibited a broad visible emission with distinct sub-peaks linked to SiC bandgap transitions and carbon-rich defects. Chromaticity diagrams indicated suitability for white LED applications. Hall effect measurements showed excellent electrical properties of the as-deposited GSC film, with high carrier density and mobility, which reduced significantly after annealing, transitioning the material to a more insulating state. These findings collectively provide a comprehensive understanding of GSC thin films’ properties and their potential applications.

A facile route derived solar selective nickel-cobalt oxide thin films via spraying process

Abstract This work focuses on understanding the role of annealing temperature on the solar selective performance of nickel-cobalt oxide thin films successfully sprayed onto Al substrates using the spray pyrolysis technique. The synthesized nickel-cobalt oxide thin films (~ 725± 20 nm thick) were post annealed at (400, 500 and 600) °C. The XRD and FESEM outcomes appeared high crystalline quality with crystal grains in the range of (27 – 52) nm and improved surface morphology for the sprayed thin films. The optical properties reflect solar absorptance ~ (85.2 %) and the thermal emittance ~ (4.45 %). The hardness and the Young’s modulus were (19.1 GPa) and (104 GPa) respectively. The aforementioned results are for the film annealed at 600 °C. The prepared and post annealed nickel-cobalt oxide thin films show band gap energies in the range of (1.15 – 1.38) eV. The nickel-cobalt oxide thin films also possess excellent thermal stability at higher temperature which makes them interesting candidate for solar absorbing and thermal collector applications.

Growth of CuO NPs layers on TiO2 NTs using vacuum thermal evaporation

CuO/TiO2 composites have been reported to exhibit higher potential for various applications (electronics, energy storage, and sensor technology…). This study investigates the impact of different film thicknesses on the properties of CuO NPs on TiO2 NTs. CuO NPs were deposited onto TiO2 NTs using vacuum thermal evaporation, with thicknesses ranging from 5 to 30 nm. A quartz crystal monitor measured evaporation rate and film thickness at a substrate temperature of 350 °C. Following the deposition process, the samples were thermally treated through air annealing at 400 °C for 1 h.XRD analysis showed that all films had an anatase phase. The annealed sample also had a confirmed CuO phase, indicating good crystallinity. Crystallite size and strain varied with film thickness, assessed using the Williamson-Hall method and Rietveld refinement. The deposition and distribution of CuO on TiO2 NTs were verified using Scanning Electron Microscopy (SEM) combined with energy dispersive spectroscopy (EDS). Optimizing the materials nanostructures requires controlling film thickness and annealing. Insights from this study can improve nanomaterial fabrication techniques, which could enhance their performance in technological applications.

A new way to tune photocatalytic activity, surface morphology, and structural/optical parameters of ZrO2 thin films using different Zr sources along with annealing temperature and film thickness

A new way to tune photocatalytic activity, surface morphology, and structural/optical parameters of ZrO2 thin films using different Zr sources along with annealing temperature and film thickness

Effects of implementing dual-step nitrogen ambient for growth and post-deposition annealing of Ga2O3 films sputtered on silicon

Effects of implementing dual-step nitrogen ambient for growth and post-deposition annealing of Ga2O3 films sputtered on silicon

Plasmonic Ag Nanoparticles on SiC for Use as SERS Substrate and in Integrated Optical Sensors for Bio-Chemical Applications

Development of optical chemical sensors for the detection of specific toxic chemicals at ultratrace levels and analysis of complex mixtures is crucial for new green and safe technologies [1, 2]. Metallic structures confined at the nanoscale acquire interesting properties such as strongly localizing E fields on their surfaces through Plasmonic Resonance under stimuli of light at certain wavelengths. This nanostructures are called plasmonic structures [3–5]. This effect is exploited to amplify the optical signal obtained by the molecules of interest, located near plasmonic structures [3, 6]. Purpose of the work is the development of innovative, easy to manufacture and cheap optical active layer consisting of Plasmonic Ag Nanoparticles on a Wide Band Gap semiconductor material such as Silicon Carbide to be used as substrate for Surface Enhanced Raman Scattering or for the fabrication of integrated optical sensor for remote chemical and biological applications. In this contest, the phenomenon of Ag thin film thermal dewetting on SiC substrate was implemented to develop a simple nanoparticles synthetic approach. Scanning Electron Microscopy confirmed the formation of Ag nanoparticles by thermal annealing of thin silver film. 4-MBA was used as probe molecule for SERS phenomenon investigation. The formation of a covalent bond between the silver nanostructures, acting as plasmonic "hot spots", and the species of interest enable its detection at very low concentrations, in the range of 10-5 M or less, in both Raman and UV-Vis configurations.

High‐throughput study of X‐ray‐induced synthesis of flower‐like CuxO

AbstractCuxO with flower‐like hierarchical structures has attracted significant research interest due to its intriguing morphologies and unique properties. The conventional methods for synthesizing such complex structures are costly and require rigorous experimental conditions. Recently, the X‐ray irradiation has emerged as a promising method for the rapid fabrication of precisely controlled CuxO shapes in large areas under environmentally friendly conditions. Nevertheless, the morphological regulation of the X‐ray‐induced synthesis of the CuxO is a multi‐parameter optimization task. Therefore, it is essential to quantitatively reveal the interplay between these parameters and the resulting morphology. In this work, we employed a high‐throughput experimental data‐driven approach to investigate the kinetics of X‐ray‐induced reactions and the impact of key factors, including sputtering power, film thickness, and annealing of precursor Cu thin films on the morphologies of CuxO. For the first time, the flower‐like CuxO nanostructures were synthesized using X‐ray radiation at ambient condition. This research proposes an eco‐friendly and cost‐effective strategy for producing CuxO with customizable morphologies. Furthermore, it enhances comprehension of the underlying mechanisms of X‐ray‐induced morphological modification, which is essential for optimizing the synthesis process and expanding the potential applications of flower‐like structures.

The effect of Ar+ and N+ ion irradiation on the thermally induced evolution of the structural and magnetic properties of Co/Pt and Pt/Co bilayered stacks

The application of Co–Pt thin films as functional elements of novel nanoelectronics and spintronics devices requires the formation of a homogeneous ferromagnetic CoPt phase with tunable magnetic properties. A diffusion-controlled synthesis of this ferromagnetic phase can be implemented through the annealing of deposited Co/Pt bilayers. Apart from thermal treatment, both structural and magnetic properties of such layered stacks can be affected by ion preirradiation. In this work, we, therefore, studied the effect of a two-stage process consisting of preirradiation with 110 keV Ar+/N+ ions followed by post-annealing in vacuum at 550°С for 30 min on the evolution of the structural, chemical, and magnetic properties of Co/Pt/substrate and Pt/Co/substrate heterostructures. The results obtained for such two-stage processing were compared to those received after single-stage vacuum annealing. It was found that when ion preirradiation is followed by annealing, the diffusion-driven intermixing of Pt and Co leading to the formation of the ferromagnetic Co–Pt phase is slowed down compared to the non-irradiated samples, which is associated with the barrier effect of implanted projectiles. Furthermore, we demonstrate that preirradiation does not compromise the magnetic properties of the samples. For instance, preirradiation leads to a coercivity increase of up to 38 % compared to the non-irradiated annealed samples which is attributed to the presence of remaining paramagnetic Pt between the grains of the ferromagnetic A1-CoPt phase. We demonstrate that the applied two-stage processing (consisting of ion preirradiation followed by thermal annealing) of magnetic thin films is a promising approach for tailoring their magnetic properties such as the in-plane coercivity, saturation, and effective magnetization.

Influence of post-thermal treatment on characteristics of polycrystalline hybrid halide perovskite nanoparticles thin film

A three-dimensional organic–inorganic hybrid halide perovskite (CH3NH3PbI2Br) nanoparticle film was synthesized using solution process in one step. Precursors’ stoichiometry was used to prepare methylammonium bromide and lead (II) bromide in dimethyl formamide. The synthesized CH3NH3PbI2Br solution was spin coated on cleaned ITO prepatterned glass substrate at 2000 rpm. In addition, the influence of post-thermal treatment on the deposited nanoparticles films was evaluated by studying the structural, optical and morphological properties using X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectrometry, UV–visible spectrophotometry, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The average crystallite sizes were calculated to be ~ 8.0, ~ 9.4, ~ 11.3 and ~ 13.1 nm of as-prepared and annealed films at 400, 500 and 600 °C, respectively. Besides, the bandgaps of 2.22 eV, 1.96 eV, 1.89 eV and 1.63 eV were extrapolated for as-prepared and annealed films at 400 °C, 500 °C and 600 °C, respectively. From J–V curves, the Jsc values of 9.4, 10.6, 11.7 and 12.8 mAcm−2, FF values of 56.99%, 57.25%, 58.94% and 59.26% and PCE values of 2.99%, 3.49%, 3.96% and 4.39% were calculated for as-prepared and annealed CH3NH3PbI2Br films at 400 °C, 500 °C and 600 °C, respectively. The percentage enhancement values of 14.32%, 24.49% and 31.89% compared to as-prepared CH3NH3PbI2Br film. Hence, post-thermal treatment of organic–inorganic halide perovskite material improved its photoconversion efficiency without sacrificing its dimensionality.

Tetrafluorosubstituted titanyl phthalocyanines: Structure of single crystals and phase transition in thin films

In this work, tetrafluorinated titanyl phthalocyanines with F-substituents in both peripheral (TiOPcF4-p) and non-peripheral (TiOPcF4-np) positions were synthesized and characterized by the methods of elemental analysis, IR and electronic absorption spectroscopies. The influence of the position of F-substituents on the structure of TiOPcF4-p and TiOPcF4-np single crystals and thin films grown by vacuum sublimation was studied. TiOPcF4-p crystallizes in the I4/m space group and its molecules form uniform stacks along the tetragonal axis. Introduction of F-substituents to non-peripheral positions leads to the change of the crystal structure: TiOPcF4-np crystallizes in the P-1 space group and its molecules are packed into 2D layers. Both phthalocyanines form oriented polycrystalline films when deposited by thermal sublimation in vacuum, but their phase composition is different from that of single crystals. The effect of post-deposition annealing of TiOPcF4-p and TiOPcF4-np films on their phase composition, morphology, optical absorption and Raman spectra, as well as conductivity was revealed. It was shown that a phase transition, which led to the appearance of an additional band in the near-IR region in the optical absorption spectrum, was observed in TiOPcF4-p films when heated, whereas no phase transition was observed in TiOPcF4-np films.

Tuning of structure, surface morphology and optical properties of spray-coated nickel tin oxide thin films by heat treatment

In this work, nickel tin oxide (NiSnO3) in a 1:1 ratio was synthesized using a simple spray pyrolysis technique followed by annealing at 450 °C for different time durations. The X-ray diffraction (XRD) revealed the polycrystalline nature with perovskite structure of NiSnO3 without the formation of any secondary phases. Annealing improved the crystallinity of the films. The annealed films exhibited a preference for orientation along the (310) plane. The largest crystallite size was obtained for 4 h of annealed film. The scanning electron microscopy (SEM) images of the films distinctly illustrate enhanced crystallinity following the annealing process. Energy-dispersive X-ray spectroscopy (EDS or EDX) indicates that the film possesses a near-stoichiometric composition. All the films resulted in more than 70 % transmittance in the visible region except for 8 h annealed. The gradual reduction of energy bandgap was observed for the sample. The four peaks at 358 nm, 415 nm, 436 nm, and 460 nm were observed in photoluminescence (PL) spectra corresponding to near band emission and defects related emissions respectively. The determined optical parameters from the present study indicate that the 4-h annealed film holds promise as a favourable option for optoelectronic and photonic devices.

Effect of deposition cycle and annealing on the structural, optical, electrical, and photoluminescence properties of SnS films obtained from rapid S-SILAR technique

AbstractIn this paper, we present an optimized procedure for depositing SnS thin films using the rapid S-SILAR technique. We also analyze the effects of deposition cycles and post-deposition annealing on various film properties. XRD analysis indicates the presence of orthorhombic and cubic phases in the films. Energy dispersive X-ray analysis confirms near-optimal stoichiometry. SEM images depict the growth of closely spaced spherical granules. High optical absorption is observed in the mid-visible to NIR region, with the absorption edge shifting towards the NIR region after annealing. The bandgap values range from 1.6 eV to 1.9 eV, which is ideal for photovoltaic applications. PL spectra show three clusters of peaks corresponding to red and green emissions. Hall measurements confirm that both the as-deposited and annealed SnS films exhibit p-type conductivity, with a hole concentration on the order of 1015 cm−3.

Annealing improves the mechanical properties in poly(butylene succinate) films with oriented lamellar structure: The effect of metastable lamellae

AbstractThe application range of biodegradable Poly(butylene succinate) (PBS) is highly dependent on its mechanical properties, which can be improved by the annealing process. In this study, the mechanical properties and microstructure of PBS films with oriented lamellar structures annealed at different temperatures were characterized. It was found that the annealing process effectively improves the elastic modulus and yield strength of the oriented PBS film with the increase of annealing temperature, which is completely different from the previous results of other oriented semicrystalline polymers such as PP, PMP, PE, and PVDF. The long periods, lateral dimensions and orientation of the lamellae of the oriented PBS film increase with the increasing annealing temperature. Meanwhile, the low‐temperature endothermic plateau in the DSC curve and the g1,r/Q in the SAXS experiment decrease with annealing temperature, indicating that increasing annealing temperature would reduce the thin and metastable lamellae in the PBS films. Compared the annealing results of oriented PBS films and that of other‐oriented semicrystalline polymers, we suggested the annealing process for the oriented PBS films would reduce the thin lamellae and form thicker lamellae, resulting in an increase in the elastic modulus and yield strength of the annealed PBS films. This study clarifies how the annealing temperature affects the microstructure and mechanical properties of the oriented semicrystalline films.