Indium-free large area Nb-doped SnO2 thin film as an alternative transparent conducting electrode

Niobium doped tin oxide (NTO) thin film deposited via facile chemical spray pyrolysis technique on to a large area (10 × 10 cm²) glass substrate exhibits better optical and electrical properties. The structural, surface, optical and electrical properties were analyzed by means of XRD, XPS, AFM, SEM-EDS, Hall Effect, and four-point probe techniques. The deposited NTO thin film was found to possess a maximum average transmittance value around 75% due to enhanced optical bandgap (3.77 eV) by Nb-dopant effect. The variation of sheet resistance of the large area (10 × 10 cm²) coated thin film over the entire region was studied at every 1 × 1 cm² area. The film doped with 1.5 wt% of Nb content showed improved carrier concentration (9.33 × 10¹⁹ cm^-3), higher free carrier mobility (39.4 cm²/V·s), improved electrical resistivity (1.69 × 10^-3 Ω cm) and low sheet resistance (26.5 Ω/□). The temperature dependent electrical measurement was carried out from 200 to 450 °C in steps of 50 °C to understand the resistance stability of the film. In addition to these studies, we report the surface work function of NTO thin film to identify its suitability in optoelectronic devices. The estimated electrical properties confirm the substitution of Nb⁵⁺ in Sn site of SnO₂ lattice. Our results indicate the optimized NTO thin film to possess promising optical and electrical transport properties to serve as a better indium-free alternate transparent conducting electrode in various optoelectronic devices.     

Electrical and optical characteristics of transparent conducting Si-doped ZnO/hole-patterned Ag/Si-doped ZnO multilayer films

Hole-patterned Ag layers were first used to form Si-doped ZnO (SZO)/hole-patterned Ag/SZO multilayers and their optical and electrical properties were characterized. Unlike conventional oxide/metal/oxide multilayers, all samples exhibited two characteristic features: (i) a sinusoidal wavelength dependence of the transmittance with double maxima, and (ii) undulation in the visible transmittance, but not in the infrared transmittance. With increasing SZO thickness, the transmittance maxima were red-shifted, and the visible transmittance window widened. The carrier concentration decreased from 7.42×10²² to 2.4×10²² cm⁻³, and the sheet resistances varied from 7 to 10 Ω/sq with increasing SZO thickness. Haacke's figure of merit (FOM) was calculated for the SZO-based multilayer films. The 40 nm-thick SZO multilayers had the highest FOM of 15.9×10^–3 Ω^–1. Finite-difference time-domain (FDTD) simulations were undertaken to interpret the measured transmittance. Based on the FDTD simulations, the undulating transmittance was attributed to surface plasmon-polaritons.     

Low-temperature growth of highly conductive and transparent aluminum-doped ZnO film by ultrasonic-mist deposition

Aluminum-doped ZnO (AZO) thin films are grown by ultrasonic-mist deposition method for the transparent conducting oxides (TCO) applications at low temperatures. The AZO films can be grown at a temperature as low as 200 °C with zinc acetylacetonate and aluminum acetylacetonate sources. The lowest resistivity of grown AZO films is 1.0×10⁻³ Ω·cm and the lowest sheet resistance of 1 μm thick films is 10 Ω/□, which is close to that of commercial indium tin oxide (ITO) or Asahi U-type SnO₂: F glass. The highest carrier concentration and mobility are 5.6×10²⁰ cm⁻³ and 15 cm²/V·sec, respectively. Optical transmittance of the AZO films is found over 75% for all growth conditions. We believe that the properties of grown AZO films in this study are the best among all reported previously elsewhere by solution processes.     

Sol–Gel‐Derived High‐Performance Stacked Transparent Conductive Oxide Thin Films

Single‐ and multi‐layer transparent conductive oxide (TCO) thin films exhibiting high performance, good packing density and low surface/interface roughness are deposited on silica glass substrates by the sol–gel method. The crystal and microstructural properties of the TCO thin films are evaluated as an alternate to films prepared by ultra‐high vacuum deposition. Tin‐doped indium oxide (ITO) thin films produced using a two‐step drying process showed low surface roughness because of dense packing structure not only horizontal but also vertical directions. As a result, electrical conductivity, carrier concentration, carrier mobility, and optical transmittance of 2.3 × 10³ S/cm, 8 × 10²⁰ cm^?3, 18 cm²/Vs, and over 98% at 500 nm, respectively, were achieved. A multilayer ZnO/ITO stacked structure was also fabricated using the sol–gel process. Our findings suggest that solution‐based methods show promise as an alternative to existing ultra‐high vacuum methods to fabricate TCO thin films.     

High ultraviolet transparent conducting electrodes formed using tantalum oxide/Ag multilayer

We investigated the optical and electrical properties of Ta₂O₅/Ag/Ta₂O₅ films as functions of the thicknesses of the Ta₂O₅ and Ag layers. It was found that with an increase in the thicknesses of the Ta₂O₅ and Ag layers from 10 to 40 nm and from 12 to 24 nm, respectively, the sheet resistance, carrier concentration, electron mobility, and resistivity of the Ta₂O₅/Ag/Ta₂O₅ film varied from 2.02 to 8.95 Ω/sq, 5.74 × 10²¹ to 2.92 × 10²² cm^–3, from 13.21 to 24.07 cm²/V·s, and from 8.89 × 10^-6 to 8.24 × 10^-5 Ω cm, respectively. The average transmittance (T_av) of the multilayer samples ranged from 57.18% to 93.99%, and it depended on the Ta₂O₅ and Ag layer thicknesses. The highest T_av of 93.99% was observed for the film with 35 nm thick Ta₂O₅ and 18 nm thick Ag layers, and the peak Haacke's figure of merit (157.04 × 10^–3 Ω^–1) was obtained for 20 nm thick Ta₂O₅ and 21 nm thick Ag layers. Ta₂O₅ (100 nm) and Ta₂O₅/Ag/Ta₂O₅ (20 nm/21 nm/20 nm) samples had optical bandgaps of 4.70 and 4.45 eV, respectively. Film Wizard simulations were conducted to understand the dependence of the transmittance of the multilayer on the thicknesses of the Ta₂O₅ and Ag layers, and phasor analyses were performed to determine how the transmittance of the Ta₂O₅/Ag/Ta₂O₅ (20 nm/21 nm/20 nm) film depended on the Ta₂O₅ layer's thickness.     

Increase the current density and reduce the defects of ZnO by modification of the band gap edges with Cu ions implantation for efficient,flexible dye-sensitized solar cells (FDSSCs)

Flexible dye-sensitized solar cells (FDSSCs) have good potential in future photovoltaic technology. The spin coating method deposited the ZnO films on indium-tin-oxide-coated polyethylene terephthalate (ITO-PET) flexible plastic substrates. These films are implanted with Cu-ions with 1 × 10¹³ ions/cm², 1 × 10¹⁴ ions/cm², and 1 × 10¹⁵ ions/cm². All the films have a hexagonal structure. The film irradiated with 1 × 10¹⁴ ions/cm² showed high crystallinity and crystallite size. Important optical properties like bandgap energy (E_g), band edges, refractive index, extinction coefficient, and dielectric constants are measured by UV–Vis spectroscopy. Bandgap energy decreases, and the refractive index increases at the fluence of Cu ions. The maximum decrease in E_g is observed at the 1 × 10¹⁴ ions/cm² dose. Photoluminescence spectra suggest that defects-related emission peaks are decreased at 1 × 10¹⁴ ions/cm² Cu ions fluency. J-V measurements have significantly improved photovoltaic performance compared to pristine ZnO-based solar cells. The highest efficiency (2.30%) is observed at a 1 × 10¹⁴ ions/cm² dose. The efficiency increase is related to improving the charge transfer ratio and shifting the fermi level toward the conduction band.     

A leaf-like structured ITO conductive transparent thin film from visible to near-infrared region with enhanced stability

ITO thin films as the optical and electrical windows to transform photons and charges have been applied in many areas. Here, a leaf-like structured particle is composed of small particles growing along three different orientations leading to low thermal stress accompanied by well transmittance (85%) in a wide wavelength range from visible to near-infrared region and a narrowed band gap 3.07 eV. The evolution of structure and electronic performance was studied to obtain the low resistivity (12 μΩ m) and enhanced stability of the film (1000 °C). The leaf-like structure can be maintained under 600 ℃ and the electrical properties can be modified in He and N₂ atmosphere, owing to the reduced defects, increased concentration of Sn and carrier mobility. Although the structure has changed after being annealed at 1000 °C in N₂, the thin film performs excellent electrical properties (?3.44 × 10²⁰ cm^?3 and 28 cm² V^?1 s^?1).     

Fabrication of highly efficient TiO2/Ag/TiO2 multilayer transparent conducting electrode with N ion implantation for optoelectronic applications

Fabrication of highly conductive and transparent TiO₂/Ag/TiO₂ (referred hereafter as TAT) multilayer films with nitrogen implantation is reported. In the present work, TAT films were fabricated with a total thickness of 100 nm by sputtering on glass substrates at room temperature. The as-deposited films were implanted with 40 keV N ions for different fluences (1×10¹⁴, 5×10¹⁴, 1×10¹⁵, 5×10¹⁵ and 1×10¹⁶ ions/cm²). The objective of this study was to investigate the effect of N⁺ implantation on the optical and electrical properties of TAT multilayer films. X-ray diffraction of TAT films shows an amorphous TiO₂ film with a crystalline peak assigned to Ag (111) diffraction plane. The surface morphology studied by atomic force microscopy (AFM) and field emission scanning electron microscope (FESEM) revealed smooth and uniform top layer of the sandwich structure. The surface roughness of pristine film was 1.7 nm which increases to 2.34 nm on implantation for 1×10¹⁴ ions/cm² fluence. Beyond this fluence, the roughness decreases. The oxide/metal/oxide structure exhibits an average transmittance ~80% for pristine and ~70% for the implanted film at fluence of 1×10¹⁶ ions/cm² in the visible region. The electrical resistivity of the pristine sample was obtained as 2.04×10⁻⁴ Ω cm which is minimized to 9.62×10⁻⁵ Ω cm at highest fluence. Sheet resistance of TAT films decreased from 20.4 to 9.62 Ω/□ with an increase in fluence. Electrical and optical parameters such as carrier concentration, carrier mobility, absorption coefficient, band gap, refractive index and extinction coefficient have been calculated for the pristine and implanted films to assess the performance of films. The TAT multilayer film with fluence of 1×10¹⁶ ions/cm² showed maximum Haacke figure of merit (FOM) of 5.7×10⁻³ Ω⁻¹. X-ray photoelectron spectroscopy (XPS) analysis of N 1s and Ti 2p spectra revealed that substitutional implantation of nitrogen into the TiO₂ lattice added new electronic states just above the valence band which is responsible for the narrowing of band gap resulting in the enhancement in electrical conductivity. This study reports that fabrication of multilayer transparent conducting electrode with nitrogen implantation that exhibits superior electrical and optical properties and hence can be an alternative to indium tin oxide (ITO) for futuristic TCE applications in optoelectronic devices.     

Reformulation of bone china body for the reduction of pyroplastic deformation

This work is aimed to decrease the pyroplastic deformation using sodium feldspar and potassium feldspar in bone china revealing the viscosity and crystalline phase effect. For this, we reformulated the traditional bone china recipe considering the amount and ratio of fluxing agents. In the first group, sodium feldspar (coded as Na-F) and potassium feldspar (coded as K-F) were introduced individually into the body from 20 to 35 wt.%. In the second group, we fixed the feldspar amount to 35 wt.% but changed the Na-F/K-F ratio to 1/3–1/2–1/1–2/1–3/1. Optical dilatometry measurements revealed that K-feldspar reduced the sintering temperature by about 50°C compared to Na-feldspar. Densified 35% K-F and 35% Na-F bodies showed very low pyroplastic index (PI) such as 5.36 × 10^–6 cm⁻¹ (at 1150°C) and 7.46 × 10⁻⁶ cm⁻¹ (at 1200°C), respectively, whereas Na-F/K-F 1/3 sample exhibited the lowest PI (3.58 × 10⁻⁶ cm⁻¹) at very low sintering temperature (at 1150°C). Microstructural analysis showed that the dissolution of residual quartz grains and the homogeneity of the distribution of the crystal phases support decrease in pyroplastic deformation.     

Oxidation behavior and electrical properties of metal interconnects with Ce-doped Ni–Mn spinel coatings

To improve the high-temperature oxidation resistance and electrical conductivity of ferritic stainless steels, protective Ce-doped NiMn₂O₄ spinel coatings were fabricated on the surface of SUS430 steel by electrophoretic deposition (EPD). The phase structure and microstructure of Ce-doped NiMn₂O₄ in both powder and coating forms were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The high-temperature oxidation of the NiMn₂O₄ spinel coating before and after Ce doping in the air at 800 °C for 168 h was studied by weight gain experiments. The area-specific resistance (ASR) of coatings was measured by a standard four-probe method. It was found that the Ce-doped NiMn₂O₄ spinel powder displayed a stable structure, high crystallinity, fine grain size, and decreased agglomeration when the Ce content was fixed at 0.05 mol?L^?1. The oxidation kinetics of NiMn₂O₄-coated SUS430 steel before and after Ce doping obeyed a parabolic law with parabolic rate constants of 4.58 × 10^?15 g² cm^?4 s^?1 and 1.83 × 10^?15 g² cm^?4 s^?1, respectively. When oxidized at 800 °C for 50 h, the ASR value of the coated samples before and after Ce doping stabilized at about 15.2 mΩ?cm² and 14.5 mΩ?cm², respectively. This work demonstrated that the Ce-doped NiMn₂O₄ spinel coating improved the high-temperature oxidation resistance and the electrical conductivity of metal interconnects.     

Characteristics of Transparent Conducting W‐Doped SnO2 Thin Films Prepared by Using the Magnetron Sputtering Method

Tungsten‐doped SnO₂ (WTO) thin films with a given thickness of about 300 nm have been prepared by magnetron sputtering with a substrate temperature in the range 400°C–700°C. The effects of substrate temperature on the structural, optical, and electrical properties and of WTO thin films have been investigated. A texture transition from (1 1 0) to (2 1 1) crystallographic orientations has experimentally been found by X‐ray diffraction measurements as substrate temperature is raised. It was found that all thin films showed smooth surface with no cracks and high transparency (>85%) with the optical band gap ranging from 4.22 to 4.32 eV. The mobility varied from 12.89 to 22.48 cm²·(V·s)^?1 without reducing the achieved high carrier concentration of about 1.6 × 10²⁰ cm^?3. Such an increase in mobility is shown to be clearly associated with the development of (2 0 0) but concurrent degradation of (1 1 0) in WTO thin films.     

Optical properties of Er3+ and Yb3+/Er3+-doped NaF-Na2SO4-Al(PO3)3 fluoro-sulfo-phosphate glasses

Fluoro-sulfo-phosphate (FPS) glass is of current interest as potential material for laser application due to its good glass-forming ability, thermal, and chemical stability as well as the complicated local environment for incorporated species. Herein, the physical and luminescent properties of Er³⁺ and Yb³⁺/Er³⁺-doped FPS glasses vs S/F ratio are investigated comprehensively. The low melting temperature (750°C) leads to fewer ingredients evaporation and easier operation. The sulfate addition depolymerizes the structure of FPS glasses, leading to either monotonic or nonmonotonic variations of physical properties, while no deterioration in thermal and limited one in chemical stability is caused. The addition of sulfate also modifies the local structure around optical active species and thus, leading to higher emission cross section (1.52 × 10⁻²⁰ cm²), effective linewidth (68.4 nm), figure of merit (5.61 × 10⁻²³ s cm²), gain bandwidth (102.44 × 10⁻²⁷ cm³), and energy-transfer microparameters (51.87 × 10⁻³⁹ cm⁶/s), implying high possibility to serve as 1.5 μm laser application.     

Effect of AlN addition on the electrical resistivity of pressureless sintered SiC ceramics with B4C and C

The effect of 0–12 wt% AlN addition on the electrical resistivity of SiC ceramics pressureless sintered with 0.7 wt% B₄C and 2.5 wt% C additives was investigated. The elemental analysis of SiC grains revealed a codoping of Al and N in the SiC lattice with a higher N concentration with 1 wt% AlN addition and a higher Al concentration with 12 wt% AlN addition. The electrical resistivity decreased by four orders of magnitude (1.7 × 10⁵ → 8.3 × 10¹ Ω cm) with 1 wt% AlN addition due to the increased carrier density (1.7 × 10¹⁰ → 2.3 × 10¹⁵ cm⁻³) caused by excess N-derived donors. However, subsequent AlN addition (4 → 12 wt%) led to an increase (2.9 × 10³ → 1.2 × 10⁴ Ω‧cm) in electrical resistivity due to (1) increased Al dopants which act as deep acceptors for trapping N-derived carriers causing a decrease in carrier density (2.3 × 10¹⁵ → 5.9 × 10¹³ cm⁻³), (2) the formation of electrically insulating SiC-AlN solid solution, and (3) the presence of electrically insulating AlN grains at the grain boundaries.     

Influence of a Ni interlayer on the optical and electrical properties of trilayer GZO/Ni/GZO films

Trilayer GZO/Ni/GZO films were deposited onto polycarbonate (PC) substrates with RF and DC magnetron sputtering, and then the influence of a Ni interlayer on the optical and electrical properties of the films was investigated. A 2-nm-thick Ni interlayer decreased the resistivity to 6.4×10⁻⁴ Ω cm and influenced the optical transmittance.Although optical transmittance deteriorated with Ni insertion, the films showed a relatively high optical transmittance of 74.5% in the visible wavelength region. The figure of merit (FOM) of a GZO single layer film was 1.2×10⁻⁴ Ω⁻¹, while that of the GZO/Ni/GZO films reached a maximum of 8.2×10⁻⁴ Ω⁻¹.Since a higher FOM results in higher quality transparent-conductive oxide (TCO) films, it is concluded that GZO films with a 2 nm Ni interlayer have better optoelectrical performance than single-layer GZO films.     

Solvent-deficient method lowers grain-boundary resistivity of doped ceria

Nanoparticles of gadolinium-doped cerium oxide (GDC) were synthesized using solvent-deficient method and their sinterability and electrical properties were investigated using the powder and cold sintering process. The GDC powder was uniaxially pressed into cylindrically-shaped pellets with a mixture of nitric acid and hydrogen peroxide at 200°C to encourage particle arrangement during forming process. These bulk samples were annealed using two different temperature profiles: at 800°C for 5 hours and at 1300°C for 1 minute—800°C for 5 hours. The samples produced using HNO₃/H₂O₂ mixture showed higher relative density than ones without it. Ionic conductivity of the sample sintered through the two-step profile was obtained from electrochemical impedance spectroscopy. Although the grain conductivity for the samples (8.0 × 10⁻³ S cm⁻¹ at 500°C, and 3.3 × 10⁻² S cm⁻¹ at 700°C) is on par with a conventionally sintered sample, the measured total conductivity (3.9 × 10⁻³ S cm⁻¹ at 500°C, and 2.5 × 10⁻² S cm⁻¹ at 700°C) is about 10 times higher than the conventionally sintered one and is comparable to the values seen in the previous studies for GDC which employed higher sintering temperature, pointing to the effectively lower grain-boundary impedance. This result could be attributed to no significant phase segregation along grain boundaries due to the low-temperature processing.     

Polycrystalline Ho: LuAG laser ceramics: Fabrication,microstructure, and optical characterization

Ho:Lu₃Al₅O₁₂(LuAG) transparent ceramics are potential 2 μm eye‐safe laser materials. Polycrystalline 0.8 at.% Ho:LuAG ceramics with high optical quality were successfully fabricated by solid‐state reactive sintering of high‐purity oxide powders. The microstructure, the optical transmission, the spectrum characteristic, and the laser performance were investigated in this paper. The average grain size of Ho:LuAG ceramics vacuum sintered at 1830°C for 30 hour is about 14 μm. The in‐line transmittance of the sample is measured to be 81.7% and 82.0% at 1000 and 2250 nm, respectively. The absorption and the emission cross sections are calculated to be 0.88 × 10^?20 cm² at 1906 nm and 1.26 × 10^?20 cm² at 2094 nm. Using a thulium‐doped yttrium‐lithium‐fluoride (Tm:YLF) laser with the central wavelength of 1907.5 nm as the pump source, 2.67 W continuous wave (CW) laser operation at 2100.74 nm was obtained with a slope efficiency of 26.5%. The beam quality factor M² was calculated to be 1.1, which indicated nearly diffraction‐limited beam propagation and the laser was the fundamental TEM₀₀ Gaussian mode.     

Ion implantation effects on the characteristics of β-Ga2O3 epilayers grown on sapphire by MOCVD

In this study, the Si-ions implantation technique with different doses from 1 × 10¹⁴ to 1 × 10¹⁵ cm^?2 and dose energy 30, 40 and 50 keV was used to tune the electrical properties in unintentionally doped (UID) β-Ga₂O₃ epilayers grown on the sapphire substrates by metalorganic chemical vapor deposition (MOCVD). A high quality UID β-Ga₂O₃ epilayers were fabricated using the optimized growth parameters of MOCVD. The UID and Si-ions implanted β-Ga₂O₃ epilayers were examined and results were compared with the help of X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. Si-ions implantation parameters were also simulated by stopping and range of ions in matter software (SRIM) and actual Si-ions concentration was measured by secondary ions mass spectroscopy. The electrical properties of the implanted β-Ga₂O₃ epilayers were measured by transmission length method and Hall measurements. The sheet resistivity for the β-Ga₂O₃epilayers with Si-ion dose of 1 × 10¹⁴, 6 × 10¹⁴ and 1 × 10¹⁵ cm^?2 were found as 2.047, 0.158 and 0.144 Ω cm, respectively measured by Hall measurements and the electron carrier concentrations for the above doses were 4.39 × 10¹⁸, 6.86 × 10¹⁸ and 7.98 × 10¹⁹ cm^?3. From the above results, the ion implantation was demonstrated to effectively reduce the resistivity with the high carrier concentrations.     

High-performance ITO/a-IGZO heterostructure TFTs enabled by thickness-dependent carrier concentration and band alignment manipulation

Utilization of highly conductive metal-oxide (MO) film such as indium-tin-oxide (ITO) in a channel layer has been considered as a promising strategy to realize high-mobility thin-film transistors (TFTs). However, achieving high-mobility is typically restricted by severe negative threshold voltage (V_th) shift and large off-current which are consequences of channel thickness increment. Here, to realize high-mobility MO TFTs with low V_th and off-current level, a heterogeneous ITO/amorphous indium-gallium-zinc-oxide (a-IGZO) channel structure was implemented. In the channel, the ultrathin (4 nm) ITO layer contributes to retain high electron concentration and boost the mobility, while the overlayered a-IGZO layer mitigates V_th shift and off-current increase. The ITO/a-IGZO TFTs optimized via the thickness-dependent carrier concentration of ITO and band alignment manipulation in the bilayer considerably improved the device performance showing saturation field-effect mobility of >61 cm²/V·s (average of 58.2 ± 2 cm²/V·s), subthreshold slope of <120 mV/decade (average of 129 ± 12 mV/decade), and current on/off ratio of >5 × 10¹⁰. Various electrical characterization and technological computer-aided design simulation were performed to establish a plausible mechanism explaining enhanced mobility and V_th regulation in the ITO/a-IGZO TFTs. Additionally, systematic stability tests and spectroscopic analysis were carried out to evaluate the operational stability of the device, and it is suggested that Sn ion diffusing from ITO to the heterogeneous interface can be responsible for enhanced stability by reducing the oxygen vacancy defects.     

Structures and pyroelectric properties for [111]-oriented Mn-doped rhombohedral 0.36PIN-0.36PMN-0.28PT crystal

The crystal structures, pyroelectric properties, and thermal stability of [111]-oriented 0.5 mol% Mn-doped 0.36Pb(In_1/2Nb_1/2)O₃-0.36Pb(Mg_1/3Nb_2/3)O₃-0.28PbTiO₃ (Mn-0.36PIN-0.36PMN-0.28PT) ternary single crystal were investigated. The temperature dependence of the Raman spectra and dielectric properties revealed that the crystal exhibited a rhombohedral (R) structure at room temperature, and ferroelectric R → tetragonal (T) and ferroelectric T to paraelectric cubic (C) phase transitions at 130 and 175°C respectively. The single crystal had a high remnant polarization of P_r = 38 μC cm^–2 and coercive field of E_C = 12 kV cm^–1 at room temperature and a frequency of f = 100 Hz. The values of P_r and E_C decreased with increasing temperature, exhibiting anomalies near their phase-transition temperatures, which coincided with changes in the Raman spectra and dielectric properties. Furthermore, at 25°C and f = 100 Hz, the single crystal had high pyroelectric coefficients of p = 8.7 × 10⁻⁴ C m⁻² K⁻¹, figures of merit for the current responsivity of F_i = 3.5 × 10⁻¹⁰ m V⁻¹, the voltage responsivity of F_v = 0.08 m² C⁻¹, and the detectivity of F_d = 30.1 × 10⁻⁵ Pa^−1/2. These values were weakly dependent on temperature below 120°C. In addition, the room-temperature pyroelectric coefficients of the ternary single crystal maintain over 83% of the original value at thermal annealing temperatures below 120°C. These outstanding pyroelectric properties, together with high thermal stability, indicate that [111]-oriented rhombohedral Mn-0.36PIN-0.36PMN-0.28PT ternary single crystal is a new potential candidate for infrared detection applications.     

Substantial reduction of leakage currents in La/Er/Zn/Ti multielement-doped BiFeO3 multiferroic thin films

Multi-element doping is an effective method to suppress the leakage of BiFeO₃ (BFO). A systematic study on the effect of various elements (La, Er, Zn, Ti) doping on the leakage performance, mechanism and other electrical properties of BFO films was performed As the kinds of doping elements increases, the leakage current density of the BFO film gradually decreases. The leakage current density is gradually reduced from 5.78 × 10^?2 A/cm² doped with one element (La) to 1.25 × 10^?2 A/cm² doped with two elements (La, Ti), 4.13 × 10^?3 A/cm² doped with three elements (La, Ti, Zn), and 4.53 × 10^?4 A/cm² doped with four elements (La, Er, Zn, Ti). Finally, compared with pure BFO films, the leakage current density in doped BFO films is reduced by two orders of magnitude. Moreover, the conduction mechanism in doped BFO films is gradually changed from space charge limited current to ohmic conduction. This work provides an effective method to ameliorate the leakage of ferroelectric materials and lays a foundation for the practical application of BFO-based films.