Indium Doping Concentration Research Articles

Tuning of bandgap for warm white light emissions in indium-doped cesium metal halide perovskites by solvothermal method

Cesium-based perovskites, particularly Cs3Bi2Br9, doped with indium, have emerged as promising materials for energy-efficient lighting, notably in white light-emitting diodes (WLEDs). This study aimed to address environmental concerns associated with lighting technology by employing solvothermal synthesis to fabricate these materials. Comprehensive characterization techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), and photoluminescence spectroscopy (PL), were applied to assess their properties. XRD analysis confirmed the formation of Cs3Bi2Br9 with a trigonal crystal structure and indium doping induced significant changes in the material’s color and crystal lattice. TEM imaging, even after six months, revealed the presence of stable nanocrystals, indicating the material’s durability in practical applications. UV–Vis absorption and photoluminescence spectroscopy showed variable bandgaps and efficient photon emission. Notably, as the indium doping concentration increased, the emitted light shifted from blue to bluish-white, making these materials highly suitable for the synthesis of WLEDs. This research offers a promising prospect to address environmental issues associated with lighting technology while advancing energy-efficient illumination solutions.

Defect evolution induced by low-dose neutron irradiation and elastoplastic deformation mechanism of indium-doped GaN materials

The low-dose neutron irradiation defect evolution and nanoindentation response of indium (In)-doped gallium nitride (GaN) materials are investigated in this work, which is of great significance for improving the reliability and safety of nitride semiconductors in neutron irradiation environments, as well as for clarifying their mechanical properties. A numerical simulation approach based on molecular dynamics (MD) is utilized to construct wurtzite GaN models comprising Indium doping concentrations up to 2 %. Nanoindentation simulations are performed to analyze the elastoplastic deformation mechanisms of the c-plane and m-plane In-doped GaN materials. The low-dose neutron irradiation process of In-doped GaN is further simulated, and its structural changes and defects evolution are analyzed. The indentation hardness of the c-plane GaN decreases and its Young's modulus increases as the doping concentration increases. Increases in both the indentation hardness and Young's modulus are seen for the m-plane GaN with the increasing doping concentration. Moreover, the doping of indium suppresses the plastic deformation both in the c-plane and m-plane GaNs. Two types of prismatic loops formation mechanisms are unraveled, i.e. the “nested shear loops pinch-off” mechanism in the m-plane perfect GaN, and the “lasso-shape shear loop pinch-off” mechanism in the m-plane In-doped GaN. When subject to low-dose neutron irradiation, In-doped GaN materials exhibit higher resistance to the generation of irradiation defects. As the doping concentration increases, the amounts of phase transformation, Frenkel pairs, and amorphization decrease.

Influence of indium doping on electrical performance of gallium oxide thin-film transistors

In the field of oxide semiconductor thin-film transistors (TFTs), the occurrence of charge trapping in the gate dielectric and interfaces presents significant challenges to their operational stability and reliability. In this study, we present high-performing amorphous Ga2O3 TFTs created using atomic layer deposition with varying indium doping concentrations. The channel length (Lch) and channel width (Wch) are 50 and 200 μm, respectively. As the Indium concentration increases from 0% to 60%, the charge trap density (Nit) decreases, resulting in a smaller hysteresis window. The TFTs with a doping concentration of 20% are particularly noteworthy, exhibiting high field-effect mobility (22.6 cm2 V−1 s−1), lower subthreshold swing (160 mV/dec) than amorphous Ga2O3 channel devices, a high on-off current ratio (109), an appropriate threshold voltage (−1 V), and a substantial output current (26 mA/mm at VGS = 16 V).

Growth of precursor stabilized IZO thin films and study of their optical and photoluminescence properties

ZnO thin films doped with Indium were produced on glass substrates by the process of spray pyrolysis. XRD results showed a polycrystalline hexagonal wurtzite structure. The structural, PL and optical characteristics of IZO thin films were investigated with increasing doping concentration. X ray diffraction studies with increasing Indium doping concentration show a change in the preferential orientation from 0 0 2 to 1 0 1 crystal planes. UV–vis-NIR spetra was collected and the results show that the band gap of the IZO thin film was found to be 3.5 eV. The optical transmittance spectra for thin films coated with 3 at% Indium concentration revealed high transmittance of 80–90% in the visible region. Other than the characteristic blue-green emission in In-doped thin films three more PL emissions were observed.

Enhanced Nitrogen Monoxide Gas-Sensing Performance of Ti-Doped ZnO Nanostructures By SILAR

Fig. 1. Schematic illustration of SILAR fabrication process [1].The use of semiconducting metal oxides to develop highly sensitive NO gas sensors remains an important approach in the field of gas sensing applications [2]. In this research, we describe the synthesis, characterization, and application of a very promissing NO gas sensing material ZnO doped with different atomic percentages of Ti and prepared by a simple SILAR [3] method. Synthesized specimens were structurally and morphologically characterized. The NO sensing characteristics of pristine ZnO and Ti-doped ZnO were compared using a gas sensing measurement system. The sensitivity, operating temperature, and response/recovery time were systematically investigated based on the change in electrical resistance of the materials in the presence of NO. Experimental results confirmed that 50 at% Ti-doped ZnO showed a maximum response to NO gas at an operating temperature. The sensing mechanism of the pristine and Ti-doped ZnO nanostructures is discussed in detail. We believe that the Ti-doped, flower-like ZnO nanostructure is a potential material for semiconductor-oxide-based NO gas sensors. Key words: NO gas sensor, SILAR method, flower-like, Ti-doped ZnO. Acknowledgement This research was supported by the research grant 021220FD2201 “Development of highly sensitive MOS based nano-film gas sensors” from Nazarbayev University. Reference [1] B. Soltabayev, M.A. Yıldırım, A. Ateş, S. Acar, The effect of indium doping concentration on structural, morphological and gas sensing properties of IZO thin films deposited SILAR method, Mater. Sci. Semicond. Process. 101 (2019) 28–36. https://doi.org/10.1016/j.mssp.2019.05.026.[2] V.S. Bhati, M. Hojamberdiev, M. Kumar, Enhanced sensing performance of ZnO nanostructures-based gas sensors: A review, Energy Reports. 6 (2020) 46–62. https://doi.org/10.1016/j.egyr.2019.08.070.[3] T. Çorlu, I. Karaduman, M.A. Yildirim, A. Ateş, S. Acar, Effect of Doping Materials on the Low-Level NO Gas Sensing Properties of ZnO Thin Films, J. Electron. Mater. 46 (2017) 3995–4002. https://doi.org/10.1007/s11664-017-5503-z. Figure 1

Development of indium doped ZnO thin films for highly sensitive acetylene (C2H2) gas sensing

Abstract The proposed article presents optimized Indium doped ZnO thin film for acetylene gas sensor. Thin films of ZnO and Indium doped ZnO of thickness 100 nm were successfully deposited on glass substrate using resistive thermal evaporation method. Structural properties have been performed by using XRD which reveals polycrystalline nature of the thin films. Morphological studies have been performed by using FESEM which reveals the information that thin film is homogeneous and uniform. AFM showed that with the increasing of indium doping concentration in ZnO resulting increment in vertical roughness of thin films. Further sample were tested for acetylene gas sensing using Keithley source meter and multimeter. The fabricated sensor (IZO-3) showed high sensitivity magnitude of 29.06 (100 ppm), short response and recovery time of 49.28 s and 58.45 s respectively at 150 °C operating temperature. IZO-3 sensor showed good linearity with good selectivity and excellent reproducibility.

Spray deposited indium doped tin oxide thin films for organic solar cell application

Abstract Highly conducting and transparent undoped and indium doped tin oxide (SnO2:In) thin films are prepared by spray technique at different doping concentration of Indium (In). The X-ray diffraction pattern of SnO2:In thin films are confirmed the tetragonal phase of SnO2. The resistivity of SnO2:In film is increased with increased the doping concentration of In due to the effect of ionized impurity and intragrain scattering mobility. The optimized (SnO2:In) thin film is used as a photo anode in the organic solar cells (OSC) of configuration of SnO2:In/PDOT:PSS/P3HT:PCBM/Al. The photo conversion efficiency of OSC is obtained 1.06% for SnO2 layer and it was observed 0.56% for In doped SnO2 based photoanode.

Analysis of structural, optical and electrical properties of nano-particulate indium doped zinc oxide thin films

Indium doped ZnO thin films were deposited on glass substrates by spray pyrolysis technique with variation of indium concentration within a range of 0–5 at% and annealed at 500 °C for 2 h in presence of air. Preferentially oriented ZnO films along (002) plane has been obtained at 1 at% indium doping concentration. The particle size is found to be decreased with increase in dopant concentration as a result of lowering of cohesion in ZnO. The 5 at% indium doped ZnO film has a better compact morphology due to better grain boundary interactions for which it shows highest hall mobility in comparison to the all concentration of indium doped samples. The marginal band gap shift with In doping is attributed to Burstein-Moss shift. Highest thermal activation energy of 0.78 eV has been observed in case of 3 at% indium doping. The origin of the observed visible emission peaks at 450 nm, 468 nm, 480 nm, 490 nm and 670 nm are ascribed to various defects present within the bandgap.

The effect of indium doping concentration on structural, morphological and gas sensing properties of IZO thin films deposited SILAR method

In-doped ZnO thin films with 0%,1%, 3%, 5% and 7% In were deposited by Successive Ionic Layer Adsorption and Reaction (SILAR) method on glass substrates for nitric oxide (NO) gas sensing application. X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDAX) were used to evaluate the effect of In doping concentrations on properties of the films. The XRD study clearly shows the existence of the polycrystalline structure of the films. The morphological study indicates the formation of a uniform particle such as granular and nano-flower structures on the surface of the films. The most important morphological change was observed at 3% indium doped thin film, which has nano-flower surface morphology. The gas sensing measurements were performed for different temperature and different NO gas concentrations. The maximum gas sensitivity was revealed at an optimal indium doping concentration of 3 at.% that achieved the highest sensitivity with a value of 22.4 for 50 ppm NO gas at 167 °C.

Structural and electrochemical studies of undoped and In3+-doped co-binary Cu2-xTe and Bi2Te3 thin films for aqueous Na–S batteries

Abstract WO3 electrodes coated with co-binary Cu2-xTe and Bi2Te3 thin films were fabricated for sodium-sulfur (Na–S) batteries. Film fabrication was controlled by adjusting the pH of the solution and the indium doping concentration. The phases of orthorhombic CuTe and hexagonal Cu2Te with rhombohedral Bi2Te3 were formed on the WO3 electrode. After In3+ doping, In3+ ions act as Frenkel defects in the Cu2-xTe structure. This indicated that In3+ ions are located at interstitial sites in the Cu2-xTe structure with higher defect creation energy. Furthermore, more interconnected-like nanoparticles and reduced porosity were observed, thereby indicating that indium segregation with grain boundaries presented and contributed to an enhancement of the surface mobility, nucleation density, and a smoother surface. For electrochemical characteristics, a polysulfide solution was used as a redox electrolyte for ion transport. Optimization of the pH and indium concentration attributed to improve the exchange current density (J0) and time responses for the colored and bleached states because of faster movement of Na+ and S2− ions during inter/de-intercalation. Furthermore, optimization of the electrode by adjusting the pH and doping with indium is advantageous for both Na–S and rechargeable batteries because of long life cycle, reasonably high power and energy density of 306 W/kg and 9.35 Wh/kg, respectively. The highest specific capacity (Cs) values of the charge and discharge cycles for In3+-doped electrodes are ∼ 21 and 19 mAh/g, respectively with the coulombic efficiency approximates 100% (average value of ∼96%). This approach may provide a general path for the fabrication of undoped and In3+-doped co-binary Cu2-xTe and Bi2Te3 films on WO3 electrodes and may increase our knowledge regarding Na–S batteries for further performance improvement.

Controlled synthesis of In-doped ZnO: the effect of indium doping concentration

Three dimensional (3D) indium doped zinc oxide (In:ZnO) nanostructures are produced with the simple and reliable refluxed sol–gel technique. The influence of indium (In) doping concentration was studied by varying the quantity of In-dopant during synthesis. The morphologies of the produced samples observed using FE-SEM and TEM are nanoplates, flower and prism like. The hierarchical nanoprisms are aggregated for the evolution of nanoflower like structure with increased length and the width size of the prism. The produced In:ZnO is hexagonal wurtzite in structure with increased crystallite size from 21.7 to 32.3 ± 0.01 nm as In-doping level increased from 0 to 6.5 at.%. An improved crystal quality was revealed with decreased line broadening of the X-ray diffraction (XRD) measurements. The lattice parameters obtained from XRD measurements are observed to increase due to the incorporation of larger In3+ ionic radius at the Zn2+ ion lattices. The expansion of the lattice due to tensile strain caused the XRD diffraction peaks to shift towards the smaller angle. The bond length and dislocation density variations are in agreement with the variations of crystallite size and lattice parameters. The absorption band edge acquired using the UV–Vis diffuse reflectance measurements were observed to have red shifted due to the increased crystallite size with the increase in In-doping. The optical energy band gap decreased uniformly from 3.27 to 3.21 ± 0.01 eV as the amount of In-doping increased; which is in the range for optoelectronics device applications. Photoluminescence measurements depict both the near band gap emission at around 283 nm and deep level emission at about 618 nm. Both the emission bands were red shifted due to the incorporation of larger In3+ ion. An appropriate doping of group III In atom using the controlled refluxed sol–gel synthesis method helps to modify the material properties of ZnO for possible nano and microscale optoelectronics applications.

Effect of indium doping on motions of 〈a〉-prismatic edge dislocations in wurtzite gallium nitride

The influences of indium doping on dynamics of 〈a〉-prismatic edge dislocation along shuffle plane in wurtzite GaN have been investigated employing classical molecular dynamics (MD) simulations. The dependence of dislocation motion mode and dislocation velocity on indium doping concentration, temperature, and applied shear stress was clarified. Moreover, the simulation results were further analyzed using elastic theory of dislocation and thermal activation theory of dislocation motion, showing excellent agreement with the simulation. Our findings help gain deep insights into modifying dynamic behaviors of TDs through the alloying doping and offer generic tools to the study of other wurtzite materials of promising application prospects, such as AlGaN and ZnO.

Effect of Indium Doping on the Structural and Optical Properties of CdO thin films

The aim of this study is to investigate the effect of indium doping on structural and optical characteristics of CdO thin films prepared by spray pyrolysis. According to x-ray diffraction analysis, the studied samples are polycrystalline with preferred orientation along (111) orientation. The surface topography determined by AFM and SEM indicates that the surface roughness and root mean square (RMS) values were increased as the indium doping concentration increased. The determinedoptical energy gap were found to lie between (2.47-2.84)eV.

Enhanced gas sensing properties of indium doped ZnO thin films

Indium doped ZnO (InxZn1-xO, 0 ≤ x ≤ 0.05) thin films were deposited on to soda lime glass substrate by employing spray pyrolysis as deposition technique. Effect of doping concentration on characteristics of thin films were examined by XRD, SEM, UV-Visible spectroscopy, electrical and gas sensing measurements. XRD analysis demonstrates polycrystalline nature of thin films and also shows the shift in orientation from (002) to (101) crystal plane with increase in indium doping concentration. Surface morphological analysis shows the formation of homogeneous particle like nanostructures. Optical transmittance determined from UV-Visible spectroscopy was in the range of 80–95%, which was decreasing with increase in indium doping concentration. Maximum electrical conductivity was achieved at an optimal indium doping concentration of 3 at.%. The gas sensing properties were examined for different concentration of volatile organic compounds like acetone, ethanol and methanol for different doping levels. In0.03Zn0.97O thin films showed good sensitivity towards ethanol, with sensitivity of 30% towards 25 ppm of ethanol.

Enhanced photorefractive properties of indium co-doped LiNbO3:Mo crystals

We grew a set of indium and molybdenum co-doped lithium niobate crystals with various indium doping concentrations and investigated their photorefractive properties at different wavelengths (442, 488 and 532 nm). It was found that the diffraction efficiency of 1.0 mol% indium and 0.5 mol% molybdenum co-doped lithium niobate crystal could reach 61.57% at 488 nm. Moreover for 3.0 mol% indium and 0.5 mol% molybdenum co-doped lithium niobate crystal, the response time was greatly shortened to 0.61, 0.76, and 0.74 s at 442, 488, and 532 nm, respectively, while the photorefractive sensitivity reached as high as 7.35 cm/J at 442 nm. These results indicate that co-doping of indium is an efficient way to further enhance the photorefractive properties of molybdenum-doped lithium niobate crystal.

Analysis of Carrier Transport in n-Type Hg1−xCdxTe with Ultra-Low Doping Concentration

Mercury cadmium telluride (HgCdTe, or MCT) with low n-type indium doping concentration offers a means for obtaining high performance infrared detectors. Characterizing carrier transport in materials with ultra low doping (ND = 1014 cm−3 and lower), and multi-layer material structures designed for infrared detector devices, is particularly challenging using traditional methods. In this work, Hall effect measurements with a swept B-field were used in conjunction with a multi-carrier fitting procedure and Fourier-domain mobility spectrum analysis to analyze multi-layered MCT samples. Low temperature measurements (77 K) were able to identify multiple carrier species, including an epitaxial layer (x = 0.2195) with n-type carrier concentration of n = 1 × 1014 cm−3 and electron mobility of μ = 280000 cm2/Vs. The extracted electron mobility matches or exceeds prior empirical models for MCT, illustrating the outstanding material quality achievable using current epitaxial growth methods, and motivating further study to revisit previously published material parameters for MCT carrier transport. The high material quality is further demonstrated via observation of the quantum Hall effect at low temperature (5 K and below).

Analysis of Indium Oxidation State on the Electronic Structure and Optical Properties of TiO₂.

Due to the high formation energy of Indium interstitial defect in the TiO2 lattice, the most probable location for Indium dopant is substitutional sites. Replacing Ti by In atom in the anatase TiO2 shifted the absorption edge of TiO2 towards visible regime. Indium doping tuned the band structure of TiO2 via creating In 5p states. The In 5p states are successfully coupled with the O 2p states reducing the band gap. Increasing In doping level in TiO2 improved the visible light absorption. Compensating the charge imbalance by oxygen vacancy provided compensated Indium doped TiO2 model. The creation of oxygen vacancy widened the band gap, blue shifted the absorption edge of TiO2 and declined the UV light absorption. The 2.08% In in TiO2 is the optimal Indium doping concentration, providing suitable band structure for the photoelectrochemical applications and stable geometrical configuration among the simulated models. Our results provide a reasonable explanation for the improved photoactivity of Indium doped TiO2.

Study of Undoped and Indium Doped ZnO Thin Films Deposited by Sol Gel Method

In this paper, we report the effects of Indium doping concentrations (from 0 to 10wt%) on the structural, morphological, and optical properties of deposited In doped ZnO (IZO) thin films prepared by the sol–gel method through the dip coating technique. X-ray diffraction (XRD) analysis indicates that all ZnO thin films have a polycrystalline nature with a hexagonal wurtzite phase with (002) as a preferential orientation. XRD results demonstrate that the particle size of ZnO decreased with the increase in Indium concentrations. Raman scattering spectra confirmed the wurtzite phase and the presence of intrinsic defects in our samples. Energy dispersive spectroscopy (EDS) and the X-ray photoelectron spectroscopy (XPS) measurements, confirmed the presence of zinc, oxygen and indium elements which is in agreement with XPS results. The photoluminescence (PL) spectra of the films exhibit defects-related visible emission peaks, with intensities differing owing to different concentrations of zinc vacancies. UV–Vis spectrometer measurements show that all the films are highly transparent in the visible wavelength region (≥ 70%) and presented two different absorption edges at about 3.21 eV and 3.7 eV, these may be correspond to the band gap of zinc oxide and indium oxide respectively.

Indium-doped SnO2 nanobelts for high-performance transparent and flexible photosensors by a facile assembly

Flexible and transparent electronics is the emerging future technology for optoelectronic devices. Recently, it has attracted considerable attention from the research community due to its prodigious commercial applications. Herein, we report highly flexible and transparent ultraviolet photosensors based on indium-doped tin oxide nanobelts with enhanced simultaneous photosensitivity and recovery speed, compared to pure SnO2 nanobelts. Optoelectronic properties of the nanobelt photosensors have been found to be strongly related to the indium doping concentration and grain size of the nanobelts. A facile assembly method has been used to prepare the well-aligned nanobelt device for UV photosensors. Excellent flexible properties of the nanobelts have been explored, which show a superior response during bending tests and almost maintain their properties after 300 bending cycles. The enhanced photosensitivity of about 70 times that of undoped SnO2 nanobelts along with a highly enhanced recovery speed of less than 1.75 s have been achieved by the precise doping of In3+ into SnO2 lattice nanobelts. All these results show that our prepared photosensors demonstrate superior mechanical, electrical, and optical properties for their use in flexible and transparent electronics.

Optical and structural study of Ga and In co-doped ZnO films

Doping with different metals leads to effective modification of structural, morphological, optical, electrical and chemical properties of ZnO films. Ga and In co-doped ZnO thin films have been succesfully obtained by the sol-gel method, using spin coating. FTIR detailed studies of undoped ZnO, In or Ga doped and In-Ga- ZnO films reveal that Ga and In co-doping affects the shapes and the intensity of the absorption bands. No clear traces of Ga–O and In–O bonds are detected. XRD analysis shows that In and Ga co-doped ZnO films posses lower crystalization compared to ZnO and ZnO:Ga. Respectively, the crystallite sizes of co-doped systems are significantly smaller compared to ZnO crystallites and closed to that of ZnO:Ga 3 films. The lattice parameters, texture coefficients are determined from XRD data. Optical characterization shows that the In and Ga co-doped ZnO films are found to be less transparent compared to sol-gel derived ZnO and ZnO:Ga films. The optical band gaps of co-doped films are estimated as a function of the annealing temperatures, ranging from 3.41 up to 3.28eV. It has been observed that the optical band gap values of In-Ga-Zn-O films are strongly dependent on the indium doping concentration.