Luminescence properties of Cu‐ion‐implanted and annealed ZnO thin films deposited by chemical vapor deposition and pulsed laser deposition

Ion implantation techniques were used to study the effect of an MgO additive on the luminescence properties induced by Cu in ZnO thin films. Cu ions (accelerating voltage of 75 keV, dose of 4.5 × 10¹⁴ ions/cm²) were implanted at room temperature in nondoped and Mg‐doped ZnO thin films. After annealing, emissions in the visible region originating from Cu phosphor were observed at 510 nm in CVD‐ZnO and at 450 nm in Mg‐doped ZnO (MZO) thin films. The Cu depth profile shows distortion in the low‐concentration region of CVD‐ZnO. After the annealing, the Cu implant was homogenized in thin films, and then the Cu concentration was determined to be 1.5 × 10¹⁹ ions/cm³ in CVD‐ZnO and 5.6 × 10¹⁸ ions/cm³ in MZO thin films. Copyright © 2005 John Wiley & Sons, Ltd.     

Structural,electrical and optical properties of tin doped cadmium oxide thin films obtained by sol–gel

Transparent and conducting tin doped cadmium oxide thin films were obtained by mixing cadmium oxide and tin oxide precursor solutions by the sol–gel method. Different tin contents in solution were studied: 0, 0.5, 1, 2, 3, 5 and 10 at.%. The films were sintered at 550 °C and, after that, annealed in N₂/H₂ gas mixture, in order to decrease their resistivity. X-ray diffraction patterns showed that doping of tin diminishes the [111] light preferred orientation of films and provokes a decrease of the average crystallite size from 30 to 12 nm. Atomic force microscopy images revealed morphological changes with the addition of tin content. All the films showed a high transmission around 75 % in the 600 < λ < 1,700 nm range and a shift of the absorption edge towards the blue region as the tin concentration was increased. The cadmium oxide films doped with 1 at.% of tin showed the lowest resistivity of 5.7 × 10^?4 Ω cm and a band gap energy value of 2.7 eV. For their characteristics, these CdO:Sn films are good candidates as transparent conductive electrodes in CdS/CdTe and CdS/CIGS type solar cells.     

A High‐Performance Organic Field‐Effect Transistor Based on Platinum(II) Porphyrin: Peripheral Substituents on Porphyrin Ligand Significantly Affect Film Structure and Charge Mobility

Organic field‐effect transistors incorporating planar π‐conjugated metal‐free macrocycles and their metal derivatives are fabricated by vacuum deposition. The crystal structures of [H₂(OX)] (H₂OX=etioporphyrin‐I), [Cu(OX)], [Pt(OX)], and [Pt(TBP)] (H₂TBP=tetra‐(n‐butyl)porphyrin) as determined by single crystal X‐ray diffraction (XRD), reveal the absence of occluded solvent molecules. The field‐effect transistors (FETs) made from thin films of all these metal‐free macrocycles and their metal derivatives show a p‐type semiconductor behavior with a charge mobility (μ) ranging from 10^?6 to 10^?1 cm² V^?1 s^?1. Annealing the as‐deposited Pt(OX) film leads to the formation of a polycrystalline film that exhibits excellent overall charge transport properties with a charge mobility of up to 3.2×10^?1 cm² V^?1 s^?1, which is the best value reported for a metalloporphyrin. Compared with their metal derivatives, the field‐effect transistors made from thin films of metal‐free macrocycles (except tetra‐(n‐propyl)porphycene) have significantly lower μ values (3.0×10^?6–3.7×10^?5 cm² V^?1 s^?1).     

Electrochemical Fabrication and Properties of Highly Ordered Fe‐Doped TiO2 Nanotubes

Highly‐ordered Fe‐doped TiO₂ nanotubes (TiO₂nts) were fabricated by anodization of co‐sputtered Ti–Fe thin films in a glycerol electrolyte containing NH₄F. The as‐sputtered Ti–Fe thin films correspond to a solid solution of Ti and Fe according to X‐ray diffraction. The Fe‐doped TiO₂nts were studied in terms of composition, morphology and structure. The characterization included scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, UV/Vis spectroscopy, X‐ray photoelectron spectroscopy and Mott–Schottky analysis. As a result of the Fe doping, an indirect bandgap of 3.0 eV was estimated using Tauc’s plot, and this substantial red‐shift extends its photoresponse to visible light. From the Mott–Schottky analysis, the flat‐band potential (E_fb) and the charge carrier concentration (N_D) were determined to be ?0.95 V vs Ag/AgCl and 5.0 ×10¹⁹ cm^?3 respectively for the Fe‐doped TiO₂nts, whilst for the undoped TiO₂nts, E_fb of ?0.85 V vs Ag/AgCl and N_D of 6.5×10¹⁹ cm^?3 were obtained.     

Characterization of Tin(IV) Oxide Thin Films Prepared by Atmospheric Pressure Chemical Vapor Deposition of cis‐[SnCl4{OC(H)OC2H5}2]

A new single‐source precursor, [SnCl₄{OC(H)OC₂H₅}₂], prepared by treating tin tetrachloride with ethyl formate (1:2 ratio) was developed for the deposition of tin oxide thin films on glass substrates. The compound [SnCl₄{OC(H)OC₂H₅}₂] is highly volatile and provides very high growth rates (up to 100Å s^?1 at 560 °C) in an atmospheric pressure chemical vapor deposition (APCVD) reactor. More significantly, the compound does not decompose to tin oxide below 320 °C, thereby minimizing the formation of particles in the vapor above the growing tin oxide film. To prepare highly conducting fluorine doped tin oxide (SnO₂:F) films 2,2,2‐trifluoroethyl trifluoroacetate was used as the source of fluoride. High quality SnO₂:F films were deposited at 560 °C with a flow rate of 2 mL fluoride reagent hr^?1; typical film properties are resistivity of 5.9 X 10^?4 Ω cm, Hall mobility of 27.3 cm² V^?1 s^?1, carrier concentration of 3.9 X 10²⁰ cm^?3 and percent transmission ranging from 86 to 88 %. The best films of SnO₂:F possess transparencies as high as 90 % (750 nm), sheet resistances as low as 7 Ω sq^?1 and Haacke's figure of merit as high as 29 X 10^?3 (750 nm). The newly developed APCVD reactor and the chemistry were optimized with respect to structural, electrical and optical properties of the films by adjusting the substrate temperature, gas flow rates and the amount of fluoride present in the vapor stream. Growth rates with respect to deposition time, substrate temperature and flow rates of precursors were found to be similar for both undoped (SnO₂) and doped (SnO₂:F) samples. The SnO₂:F films possess larger grains than the SnO₂ which may account for the lower resistivity and the higher mobility in the SnO₂:F samples.     

Electrical,Optical, and Structural Properties of SnO2: F Films as a Function of Fluoride Precursor Concentration and Temperature

Atmospheric pressure chemical vapor deposition (APCVD) employing the precursor system of tin tetrachloride, ethyl formate, and 2,2,2‐trifluoroethyl trifluoroacetate vapors that were transported to hot glass substrates to deposit fluorine doped tin dioxide thin films. The system is optimized with respect to the substrate deposition temperature and to the amount of fluoride added to the precursor stream and the resultant structural, electrical and optical properties compared. Increasing the substrate temperature from 360 °C to 610 °C resulted in an approximately linear increase in thickness of the tin dioxide films. However, the resistivity decreased from 1.8 × 10^–2 Ω · cm at 360 °C to a minimum of 5.9 × 10^–4 Ω · cm at 560 °C and increased to 9.4 × 10^–4 Ω · cm at 610 °C. While maintaining a substrate temperature of 560 °C different amounts of fluorine precursor was introduced into the carrier stream, from 0 mL · h^–1 to 5 mL · h^–1, resulting in a decrease in resistivity (ρ) from 5.3 × 10^–2 Ω · cm at 0 mL · h^–1 to a minimum of 5.9 × 10^–4 Ω · cm at 2 mL · h^–1 and then increased to 1.0 × 10^–3 Ω · cm at 5 mL · h^–1. As the amount of fluoride is increased a concommittent increase in carrier concentration results until the point of overdoping the film produces an increase in scattering sites that increases resistivity. Best films were deposited at 560 °C and when the fluoride precursor flow rate was 2 mL · h^–1.     

Transparent conductive tungsten-doped tin oxide thin films synthesized by sol–gel technique on quartz glass substrates

Transparent conductive tungsten-doped tin oxide (SnO₂:W) thin films were synthesized on quartz glass substrates by sol–gel dip-coating method. It was found that the films were highly transparent and the average optical transmission was about 90% in the visible and near infrared region from 400 to 2,500 nm. The optical band gap is about 4.1 eV. The lowest resistivity of 5.8 × 10^?3 ohm cm was obtained, with the carrier mobility of 14.2 cm² V^?1 s^?1 and carrier concentration of 7.6 × 10¹⁹ cm^?3 in 3 at.% W-doping films annealed at 850 °C in air. The structural properties, surface morphology and chemical states for the films were investigated.     

Conductive triethylene glycol monomethyl ether substituted polythiophenes with high stability in the doped state

Synthesis of two conducting polymers containing 3‐hexylthiophene and 3‐[2‐(2‐(2‐methoxyethoxy)ethoxy)ethoxy]thiophene is demonstrated. In thin‐film transistors, the high‐molecular‐weight polymer shows an average mobility of 4.2 × 10^?4 cm² V^?1 s^?1. Most importantly, the polymers have high conductivity upon doping with iodine and also have high stability in the doped state with high conductivities measured even after 1 month. Furthermore, the doping causes transparency to thin films of the polymer and the films are resistant to common organic solvents. All these properties indicate a great potential for the iodine‐doped polymer to be used as an alternative to commercially available poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate). © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 1079–1086     

Preparation and nonlinear optical properties of Au nanoparticles doped TiO2 thin films

Nano-sized noble metal nanoparticles doped dielectric composite films with large third-order nonlinear susceptibility due to the confinement and the enhancement of local field were considered to be applied for optical information processing devices, such as optical switch or all optical logical gates. In this paper, sol–gel titania thin films doped with gold nanoparticles (AuNPs, ~10 nm in average size) were prepared. AuNPs were firstly synthesized from HAuCl₄ in aqueous solution at ~60 °C, using trisodium citrate as the reducing agent, polyvinylpyrrolidone as the stable agent; then the particle size and optical absorption spectra of the AuNPs in aqueous solutions were characterized by transmitting electron microscopy and UV–Vis–NIR spectrometry. Sol–gel 2AuNPs–100TiO₂ (in %mol) thin films (5 layers, ~1 μm in thickness) were deposited on silica glass slides by multilayer dip-coating. After heat-treated at 300–1,000 °C in air, the AuNPs–TiO₂ thin films were investigated by X-ray diffraction, scanning electron microscopy and atomic force microscopy. The nonlinear optical properties of the AuNPs–TiO₂ thin films were measured with the Z-scan technique, using a femtosecond laser (200 fs) at the wavelength of 800 nm. The third-order nonlinear refractive index and nonlinear absorption coefficient of 2AuNPs–100TiO₂ films were at the order of 10^?12 cm²/W, and the order of 10^?6 cm/W, respectively, and the third-order optical nonlinear susceptibility χ⁽³⁾ was ~6.88 × 10^?10 esu.     

Electrical,optical, and structural characterization of p‐type N‐doped SnO thin films prepared by thermal oxidation of sputtered SnNx thin films

We present a study of electrical and optical properties of nitrogen‐doped tin oxide thin films deposited on glass by the DC Magnetron Sputtering method. The deposition conditions to obtain p‐type thin films were a relative partial pressure between 7% and 11% (N₂ and/or O₂), a total working pressure of 1.8 mTorr and a plasma power of 30 W. The deposited thin films were oxidized after annealing at 250°C for 30 minutes. X‐ray diffraction results showed that the as‐deposited thin films exhibit a Sn tetragonal structure, and after annealing, they showed SnO tetragonal structure. X‐ray photoelectron spectroscopy results showed the presence of nitrogen in the samples before and after annealing. The measured physical parameters of the thin films were optical band gap between 1.92 and 2.68 eV, resistivity between 0.52 and 5.46 Ωcm, a concentration of p‐type carriers between 10¹⁸ and 10¹⁹ cm^?3, and a Hall mobility between 0.1 and 1.94 cm²V^?1s^?1. These thin films were used to fabricate p‐type thin film transistors.     

Charge transport properties of MDMO PPV thin films cast in different solvents

Charge transport properties in thin films of Poly(2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylenevinylene) (MDMO PPV) cast using either chloroform (CF), toluene (TOL), or chlorobenzene (CB) as solvent were investigated. Hole mobility (μ) in these thin films measured using time‐of‐flight transient photoconductivity showed an increasing trend with respect to the solvent used in the same order, that is, μ_CF (2.4 × 10^?7 cm²/Vs) < μ_TOL (6.9 × 10^?7 cm²/Vs) < μ_CB (2.3 × 10^?6 cm²/Vs). Observed variations in mobilities were attributed to different morphologies of MDMO PPV chains in thin films cast using the aforesaid solvents. Nature of the interchain interactions and aggregate formation were obtained using photoluminescence (PL), Raman spectroscopy, and AFM studies. Ratio of PL peak intensities of 0–0 and 0–1 transitions, which is a direct measure of interchain interaction, was the highest in CB and lowest in CF. Variation in the relative intensities of out‐of‐plane wagging of vinylene group (～963 cm^?1 mode) in Raman spectra suggested different extent of coiling of polymer chains in these thin films. From these observations, it was elicited that aggregate size and interchain interactions are highest in CB and least in CF. AFM‐based topographic images of thin films further supported these variations in the size of aggregates. Variation in the aggregate sizes and interchain interactions explained the corresponding variation in the mobility. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1431–1439     

Construction and Characterization of Ru(II)Tris(bipyridine)‐Based Silica Thin Film Electrochemiluminescent Sensors

Ru(II) tris‐bipyridine based ECL sensors were produced by embedding the complex inside silica glass thin films deposited via a sol‐gel dipping procedure on K‐glass conducing substrates. Films were prepared starting from a pre‐hydrolyzed ethanolic solution of Si(OC₂H₅)₄ and Ru(bpy)₃Cl₂. Transparent, crack‐free and homogeneous reddish silica layers, having a thickness of 200±20 nm, were obtained. The films, either deposited at room temperature or thermally annealed at 100, 200 and 300 °C for 30 h, were structurally and chemically characterized. Ru(bpy)₃Cl₂ thermal stability was previously checked by thermogravimetric analysis (TGA). The films were investigated by X‐Ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS) and UV‐vis spectroscopy. XPS in‐depth profiles revealed a homogeneous distribution of the ruthenium complex inside the silica thin layers. SIMS data suggested that the embedded Ru(bpy)₃Cl₂ did not react with oxygen inside the oxygen‐rich silica matrix to give Ru‐O bonds. Electrochemical and ECL characterization of the thin film electrodes were made by means of cyclic voltammetry (CV) and controlled potential step experiments. The ECL sensor showed a diffusive redox behavior of the Ru(bpy)₃²⁺/Ru(bpy)₃³⁺ system. Light emission produced from the reaction between oxalic acid and the electrogenerated Ru(bpy)₃³⁺ was larger and stable when thermally treated electrodes were used after a suitable hydration period. The 300 °C treated sample was the best performing sensor both in terms of low complex leakage and sensitivity. Calibration plots relative to oxalic acid were obtained both in stationary and in flowing solutions in the concentration range 2×10^?6?3×10^?4 M. A linear behavior appeared in the former case, while in the latter a slight curvature was evident as a consequence of a finite diffusion time of the analyte inside the thin film. The signal repeatability, obtained by multiple 100 μL of 10^?5 M oxalic acid injections in flowing solutions, was better than 4%. The obtained detection limit (computed as three times the standard deviation of the base‐line noise) was 10^?6 M as oxalic acid.     

Voltammetric Determination of 3‐Nitrofluoranthene and 3‐Aminofluoranthene at Boron Doped Diamond Thin‐Film Electrode

The voltammetric behavior of 3‐nitrofluoranthene and 3‐aminofluoranthene was investigated in mixed methanol‐water solutions by differential pulse voltammetry (DPV) at boron doped diamond thin‐film electrode (BDDE). Optimum conditions have been found for determination of 3‐nitrofluoranthene in the concentration range of 2×10^?8–1×10^?6 mol L^?1, and for determination 3‐aminofluorathnene in the concentration range of 2×10^?7–1×10^?5 mol L^?1, respectively. Limits of determination were 3×10^?8 mol L^?1 (3‐nitrofluoranthene) and 2×10^?7 mol L^?1 (3‐aminofluoranthene).     

Unsymmetrical Tetradentate Schiff Bases Copper (II) Complex as Neutral Carrier for Thiocyanate‐Selective Electrode

Abstract

Three kinds of transition metal chelates of unsymmetrical tetradentate Schiff base, o‐hydroxybenzophenone‐1,2‐diaminobenzene‐pyrrole‐2‐carbaldehyde(H₂L), were synthesized to prepare anion‐selective electrodes and their anion response characteristics were investigated. The results show that the performances of the electrodes are considerably influenced by the nature of the central metals. The proposed electrode with the Cu(II)‐chelate and cationic additive demonstrated an anti‐Hofmeister selectivity sequence with a good selectivity towards thiocyanate in the following order: Thiocyanate>iodide>salicylate>perchlorate>bromide>nitrite>chloride>acetate>fluoride>nitrate>sulfite>sulfate. The electrode had an excellent linear response to thiocyanate from 3.4×10^?7 to 1.0×10^?1 M in phosphate buffer solution at pH 5.0 with a slope of ?58.7 mV per decade, a detection limit of 1.6×10^?7 M, and a fast response time within 5 s over the entire concentration series. Spectroscopic techniques and AC impedance were used to investigate the response mechanism to thiocyanate of the membrane doped with Cu(II)‐chelate. The preliminary application of the electrode for determination of thiocyanate in wastewater and urine samples is reported.     

A Metal–Organic Framework Thin Film for Selective Mg2+ Transport

The incompatibility between the anode and the cathode chemistry limits the used of Mg as an anode. This issue may be addressed by separating the anolyte and the catholyte with a membrane that only allows for Mg²⁺ transport. Mg‐MOF‐74 thin films were used as the separator for this purpose. It was shown to meet the needs of low‐resistance, selective Mg²⁺ transport. The uniform MOF thin films supported on Au substrate with thicknesses down to ca. 202 nm showed an intrinsic resistance as low as 6.4 Ω cm², with the normalized room‐temperature ionic conductivity of ca. 3.17×10^?6 S cm^?1. When synthesized directly onto a porous anodized aluminum oxide (AAO) support, the resulting films were used as a standalone membrane to permit stable, low‐overpotential Mg striping and plating for over 100 cycles at a current density of 0.05 mA cm^?2. The film was effective in blocking solvent molecules and counterions from crossing over for extended period of time.     

Highly Selective Thiocyanate Electrode Based on Bis‐bebzion Schiff Base Binuclear Copper(II) Complex as Neutral Carrier

Abstract

A highly selective polyvinyl chloride (PVC) membrane electrode, based on N,N′‐(aminoethyl)ethylenediamide bis(2‐benzoideneimine) binuclear copper(II) complex [Cu(II)‐AEBB] as neutral carrier, was prepared for thiocyanate (SCN^?) determination, which displays an anti‐Hofmeister selectivity sequence for a series of anions in the following order: SCN^?>ClO₄ ^?>Sal^? > I^?>NO₃ ^?>Br^?> Cl^?>NO₂ ^?>SO₃ ^2?>F^?>H₂PO₄ ^?>SO₄ ^2?. The electrode exhibited near‐Nernst response for SCN^? with a slope of –59.0 mV/decade over a wide concentration range (8.5×10^?7～6.8×10^?1 mol/L) with a detection limit of –5.0×10^?7 mol/L in pH 5.0 phosphate buffer solution at 25°C. Alternating current (AC) impedance and equivalent circuits were used to investigate the thiocyanate response mechanism of the membrane doped with [Cu(II)‐AEBB].     

A Compact Tetrathiafulvalene–Benzothiadiazole Dyad and Its Highly Symmetrical Charge‐Transfer Salt: Ordered Donor π‐Stacks Closely Bound to Their Acceptors

A compact and planar donor–acceptor molecule 1 comprising tetrathiafulvalene (TTF) and benzothiadiazole (BTD) units has been synthesised and experimentally characterised by structural, optical, and electrochemical methods. Solution‐processed and thermally evaporated thin films of 1 have also been explored as active materials in organic field‐effect transistors (OFETs). For these devices, hole field‐effect mobilities of μ_FE=(1.3±0.5)×10^?3 and (2.7±0.4)×10^?3 cm² V s^?1 were determined for the solution‐processed and thermally evaporated thin films, respectively. An intense intramolecular charge‐transfer (ICT) transition at around 495 nm dominates the optical absorption spectrum of the neutral dyad, which also shows a weak emission from its ICT state. The iodine‐induced oxidation of 1 leads to a partially oxidised crystalline charge‐transfer (CT) salt {( 1 )₂I₃}, and eventually also to a fully oxidised compound { 1 I₃} ? 1/2I₂. Single crystals of the former CT compound, exhibiting a highly symmetrical crystal structure, reveal a fairly good room temperature electrical conductivity of the order of 2 S cm^?1. The one‐dimensional spin system bears compactly bonded BTD acceptors (spatial localisation of the LUMO) along its ridge.     

Non‐Resonant z‐Scan Characterization of the Third‐Order Nonlinear Optical Properties of Conjugated Poly(thiophene azines)

The nonlinear optical properties of a functionalized poly(thiophene azine), namely, poly(3,4‐didodecylthiophene azine), PAZ, at the optical telecommunication wavelength of 1550 nm are investigated by means of the closed‐aperture z‐scan technique in both thin films and solutions. Values of χ⁽³⁾=(2.4±0.4)×10^?13 esu, n₂=(4.0±0.7)×10^?15 cm² W^?1, and γ=(4.5±0.7)×10^?34 esu are estimated for the third‐order (Kerr) susceptibility, the intensity‐dependent refractive index, and the molecular second hyperpolarizability of solution samples, respectively. A very small dependence on the polymer chain length is found. Markedly higher values of (4.4±1.1)×10^?11 esu, (6.6±1.0)×10^?13 cm² W^?1, and (5.0±0.8)×10^?33 esu are measured for the corresponding quantities in thick (up to 20 μm) polymer films cast on quartz plates. The enhancement of the NLO responses on going from solution to solid samples is attributed to a partially ordered structure and to the presence of interchain interactions leading to greater π‐electron delocalization in the cast polymer films. The results are compared with those previously obtained by using third‐harmonic generation (THG), taking into account that those data were measured under conditions of three‐photon resonance, whereas our z‐scan measurements are fully off‐resonance.     

Deposition of copper‐doped iron sulfide (CuxFe1−xS) thin films using aerosol‐assisted chemical vapor deposition technique

Copper‐doped iron sulfide (Cu_xFe_1?xS, x = 0.010–0.180) thin films were deposited using a single‐source precursor, Cu(LH)₂Cl₂ (LH = monoacetylferrocene thiosemicarbazone), by aerosol‐assisted chemical vapor deposition technique. The Cu‐doped FeS thin films were deposited at different substrate temperatures, i.e. 250, 300, 350, 400 and 450 °C. The deposited thin films were characterized by X‐ray diffraction (XRD) patterns, Raman spectra, scanning electron microscopy, energy dispersive X‐ray analysis (EDX) and atomic force microscopy. XRD studies of Cu‐doped FeS thin films at all the temperatures revealed formation of single‐phase FeS structure. With increasing substrate temperature from 250 to 450 °C, there was change in morphology from wafer‐like to cylindrical plate‐like. EDX analysis showed that the doping percentage of copper increased as the substrate temperature increased from 250 to 450 °C. Raman data supports the doping of copper in FeS films. Copyright © 2010 John Wiley & Sons, Ltd.     

Effect of Hydration on Silk Film Material Properties

Effects of hydration on silk fibroin film properties were investigated for water‐annealed and MeOH‐treated samples. Hydration increased thickness by 60% for MeOH‐immersed films, while water‐annealed samples remained constant. MeOH‐immersed films showed an 80% mass loss due to water, while water‐annealed lost only 40%. O₂ permeability was higher in MeOH‐immersed films with Dk values of 10^?10 (mL O₂ · cm) · (cm^?1 · s^?1 · mmHg^?1), while those of water‐annealed films reached only one fifth of this value. All films showed a decrease in Young's modulus and increased plastic deformation by two orders of magnitude when submerged in saline solution. FT‐IR showed that β‐sheet content in water‐annealed films increased with increasing water vapor pressure, while MeOH‐immersed films showed no change.