In2S3 Thin Films Research Articles

Optical and Electrical Properties of Sr-doped In2S3 Thin Films Prepared by Chemical Spray Pyrolysis Technique.

Strontium doping indium sulfide thin films (In2S3:Sr) were deposited by spray pyrolysis technique on glass substrate at temperature 310C0.The films were prepared by varying the( Sr) ratio from (0.1 , 0.5, 1.5 )% .The effect of Strontium concentration on optical and electrical properties of In2S3:Sr thin films have been studied in detail visible (UV-Vis) transmittance spectroscopy measurements revealed that the optical transmittance of films exceeds 70% in the visible and near infrared region and also the direct band gap energy of the films it decreases with doping Strontium from (2.9ev) to (2.4ev).the mobility and conductivity is increases with doping Strontium and resistivity decreased from (8.5 to 1.74) ᾩcm .

Investigation Of Some Optical And Electrical Properties Of InSe Thin Film, a Window Layer for Photovoltaic Cell Growth on Glass/GaSe Substrate by M-CBD Method

The InSe thin film was successfully grown on a glass/GaSe substrate using the modified chemical bath deposition (M-CBD) method and a group was annealed one hour at 80 °C in atmospheric conditions. The energy band gap (Eg) values of the as-deposited and annealed films were defined 1,89 eV and 1,15 eV, respectively. The transmitance values (%) of the as-deposited and annealed films were asigned %0.65, %4.46 and %11,02, %10,35 at 400 and 700 nm, respectively. The I-V characteristics of the device at different temperatures was examined, the resistivity decreased and the conductivity increased with the increasing temperature. The activation energy in low temperature region was defined 0,05 eV, while it was defined 0.6 eV in high temperature region.

Strain-Induced Bandgap Enhancement of InSe Ultrathin Films with Self-Formed Two-Dimensional Electron Gas.

Atomically thin indium selenide (InSe) is a representative two-dimensional (2D) family that have recently attracted extensive interest for their intriguing emerging physics and potential optoelectronic applications with high-performance. Here, by utilizing molecular beam epitaxy and scanning tunneling microscopy, we report a controlled synthesis of InSe thin films down to the monolayer limit and characterization of their electronic properties at atomic scale. Highly versatile growth conditions are developed to fabricate well crystalline InSe films, with a reversible and controllable phase transformation between InSe and In2Se3. The band gap size of InSe films, as enhanced by quantum confinement, increases with decreasing film thickness. Near various categories of lattice imperfections, the band gap becomes significantly enlarged, resulting in a type-I band alignments for lateral heterojunctions. Such band gap enhancement, as unveiled from our first-principles calculations, is ascribed to the local compressive strain imposed by the lattice imperfections. Moreover, InSe films host highly conductive 2D electron gas, manifesting prominent quasiparticle scattering signatures. The 2D electron gas is self-formed via substrate doping of electrons, which shift the Fermi level above the confinement-quantized conduction band. Our study identifies InSe ultrathin film as an appealing system for both fundamental research and potential applications in nanoelectrics and optoelectronics.

ENHANCEMENT IN2S3NANOSTRUCTURES OPTICAL AND ELECTRICAL CHARACTERISTICS USING SPRAY PYROLYSIS GROWTH AS PROMISING MATERIAL FOR OPTOELECTRONIC APPLICATIONS

In the present work, indium sulfide In2S3 thin films were grown on amorphous glass substrate by the chemical spray pyrolysis technique .The different molar ratio of In2S3 powder and thiocyanate ( 0.05,0.1,0.15) M used to grow In2S3 nanostructure with160nm thickness on the glass substrate under 310 Co temperature. Thickness of the films were measured by optical interferometer method. Structural properties were examined using X-Ra diffraction analysis is revealed that all the films were polycrystalline in nature with a dominant 0021peak which indicates that the In2S3 nanostructures are cubic phases. The evaluated crystallite size varied in the range 67.64-81.82nm with the increase of molarity. SEM analysis revealed that all The films have no voids and cracks. Optical properties of the grown films showed that the direct band gap values were found to decrease in the range 3.1-2.75eV which are means that it has the possibility of using indium sulfide in the manufacture of optoelectronic devices. Electrical properties using Hall effect measurement showed that all films N_type semiconductor. the conductivity for all films decreases with increasing of molarity. Results indicates the possibility of using indium sulfide in the manufacturing of detector or a gas sensor.

Effect of heat treatment in sulfur on structural, optical and electrical properties of thermally evaporated In2S3 thin films

Crystallinity, optical band gap, resistivity and photoresponse of thermally evaporated In2S3 thin films deposited at a temperature of 350 °C and further annealed in sulfur vapour at different temperature range of 200–300 °C is investigated. It is observed that with an increase of annealing temperature, predominantly β-In2S3 phase is formed and the optical band gap for indirect allowed transitions increases from 1.6 eV to 2.0 eV and for direct allowed transitions from 2.3 eV to 2.7 eV. The electrophysical properties indicate that the activation mechanism of conductivity with an activation energy in the range of 0.5–0.73 eV, which is typical for the presence of indium vacancies in the β-In2S3 crystal structure and for the replacement of sulfur by oxygen atoms. It is also noted that sulfur annealing at temperatures of 250–300 °C leads to an increase in the conductivity and photosensitivity of films, which is suitable for photovoltaic applications.

Study The Effect of Annealing on Structural and Optical Properties of Indium Selenide (InSe) Thin Films Prepared by Vacuum Thermal Evaporation Technique

In this work, InSe thin films were deposited on glass substrates by thermal evaporation technique with a deposit rate of (2.5∓0.2) nm/sec. The thickness of the films was around (300∓10) nm, and the thin films were annealed at (100, 200 and 300)°C. The structural, morphology, and optical properties of Indium selenide thin films were studied using X-ray diffraction, Scanning Electron Microscope and UV–Visible spectrometry respectively. X-ray diffraction analyses showed that the as deposited thin films have amorphous structures. At annealing temperature of 100°C and 200°C, the films show enhanced crystalline nature, but at 300°C the film shows a polycrystalline structure with Rhombohedral phase with crystallites size of 17.459 nm. The results of the UV–Visible spectrometry in the wavelength range (300 – 1100) nm showed that the band gap energy of the thin films increased with increasing annealing temperature.

Electrochemical Synthesis of In2Se3 Thin Films from Citrate Bath. Structural, Optical and Morphological Investigations

Electrochemical Synthesis of In2Se3 Thin Films from Citrate Bath. Structural, Optical and Morphological Investigations

Electrical Behavior and Photocatalytic Activity of Ag-Doped In2S3 Thin Films

Electrical Behavior and Photocatalytic Activity of Ag-Doped In2S3 Thin Films

Highly luminescent In2S3 thin films with preferred growth direction of [1 0 3

In2S3 is one of the fascinating materials for a range of optoelectronic applications due to its suitable bandgap and stability. Nonetheless, its photoluminescence (PL) originating from defect states within its bandgap were hardly reported. In this work, high quality In2S3 thin films on SiO2 substrates were synthesized by using physical vapor deposition of In2S3 powder in a hot-wall Quartz tube-furnace. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy studies of the grown In2S3 films showed that extremely high crystalline quality tetragonal β-In2S3 films were synthesized with preferred growth direction of [103]. Absorption spectroscopy revealed the In2S3 films have a direct band of ~2.66 eV. Interestingly, our In2S3 films showed an extremely strong PL peak at room temperature at ~1.6 eV. The observed strong PL from our In2S3 films can be attributed to originating from the oxygen isoelectronic substitution at the sulfur site, and its efficiency was affected by oxygen concentrations in In2S3 films. Our In2S3 thin films exhibited remarkably high PL quantum yields (QY) of up to 14% which is comparable to that of GaAs quantum wells (QWs) and CdSe quantum dots (QDs).

Al3+ Doped In2S3 Thin Films: Structural and Optical Characterization

Al3+ Doped In2S3 Thin Films: Structural and Optical Characterization

Optical emission enhancement of bent InSe thin films

In contrast to the majority of two-dimensional semiconductors such as transition metal dichalcogenides, indium selenide (InSe) possesses an intrinsic large out-of-plane oriented band-edge luminescent dipole. This unique anisotropic feature of band-edge optical emissions can be exploited to achieve enhanced optical signal in bent regions of materials created by geometrical modification. We herein investigate based on first-principle calculations the mechanism of this optical emission enhancement by modelling the photoluminescence processes in bent and flat regions of the InSe thin film. We propose in our model that the shorter-wavelength interband transition, labelled as transition B′, between the second-highest valence band and the bottom of conduction band plays an important role in the enhancing process. Our model robustly describes the dependence of optical emission enhancement in the bent InSe thin films on thickness, incident light orientation, and excitation photon energy. In particular, we found that when excitation photon energy is lower than the energy of transition B′, strong enhancement up to hundreds of times can be obtained by applying an incident light at an angle less than 70° to the InSe layers. Our results provide useful references for modulating luminescent properties of InSe films toward flexible optoelectronic device applications.

Yb/InSe/SiO₂/Au Straddling-Type Tunneling Devices Designed As Photosensors, MOS Capacitors, and Gigahertz Bandstop Filters

In this work, amorphous InSe thin films coated with 30-160-nm-thick SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> are used as an active material to fabricate multifunctional devices. The n-InSe/p-SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> layers that are deposited onto ytterbium substrates are optically and electrically characterized. It was observed that the coating of SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanosheets onto the surface of InSe enhances the light absorbability in the near-infrared range without remarkable altering of the bandgap. Significant increase in the steady-state photocurrent values accompanied by faster photocurrent responses resulted from the coating of SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanosheets. Electrically, while the Yb/InSe/Au channels display tunneling Schottky barrier characteristics, the Yb/InSe/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Au channels show pn junction features. Both channels displayed metal-oxide-semiconductors (MOS) capacitance-voltage characteristics. In addition, the analyses of the current-voltage characteristics have shown that the currents in the Yb/InSe/Au and Yb/InSe/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (30 nm)/Au channel are dominated by electric field-assisted thermionic emission (tunneling) of charge carriers through barriers of widths of 18/14 and 30/16 nm under reverse-/forward-biasing conditions, respectively. Further increase in the oxide layer thickness lowered the barrier height of the devices. On the other hand, when an ac signal of low amplitude is imposed through the device channels, the conductance, capacitance, and reflection coefficient spectra displayed bandstop filter characteristics near 1.6 GHz. The microwave cutoff frequency spectra show a remarkable increase in the cutoff frequency values as a result of the coating of InSe with SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanosheets. The features of the device assure its applicability as rectifying diodes, fast photosensors, MOS capacitors, and microwave bandstop filters.

Electrical and optical characterization of sprayed In2S3 thin films as an electron transporting layer in high efficient perovskite solar cells

This study represents the investigation of In2S3 thin films, which have been deposited with different Indium salts (Chloride, Acetate, and Nitrate) using the Chemical Spray Pyrolysis (CSP) method. The Mott-Schottky analysis has been used in case of studying the electrical properties of films such as conduction and valence band, carrier densities, Fermi level (Efn), flat band potential, and semiconductor type. In the next step, the Rb1MAFA perovskite solar cell has been simulated, and the results have been validated by the experimental data (with the least parameters for fitting). Finally, In2S3 layers have been inserted on the SnO2 layer to decrease the recombination rate and enhance the efficiency of the solar cell. The results represent that the In2S3 layers with acetate source improve the band bending at the perovskite/ETL interface, the electron transfer will increase, and the result would be an increment in the open-circuit voltage (VOC), as well as the cell PCE. The efficiency of 23.47% is the recorded PCE, which is approximately 3% more than the reference case.

Comparison of Photocatalytic Efficiency of TiO2 and In2S3 Thin Films under UV and Visible Light Irradiance

Comparison of Photocatalytic Efficiency of TiO2 and In2S3 Thin Films under UV and Visible Light Irradiance

Large-area optoelectronic-grade InSe thin films via controlled phase evolution

Indium monoselenide (InSe) is an emerging two-dimensional semiconductor with superlative electrical and optical properties whose full potential for high-performance electronics and optoelectronics has been limited by the lack of reliable large-area thin-film synthesis methods. The difficulty in InSe synthesis lies in the complexity of the indium-selenium phase diagram and inadequate understanding of how this complexity is manifested in the growth of thin films. Herein, we present a systematic method for synthesizing InSe thin films by pulsed laser deposition followed by vacuum thermal annealing. The controlled phase evolution of the annealed InSe thin films is elucidated using a comprehensive set of in situ and ex situ characterization techniques. The annealing temperature is identified as the key parameter in controlling phase evolution with pure thin films of InSe developed within a window of 325 °C to 425 °C. To exert finer stoichiometric control over the as-deposited InSe thin film, a co-deposition scheme utilizing InSe and In2Se3 pulsed laser deposition targets is employed to mitigate the effects of mass loss during annealing, ultimately resulting in the synthesis of centimeter-scale, thickness-tunable ε-InSe thin films with high crystallinity. The optimized InSe thin films possess a strong optoelectronic response, exhibited by phototransistors with high responsivities up to 103 A/W. Additionally, enhancement-mode InSe field-effect transistors are fabricated over large areas with device yields exceeding 90% and high on/off current modulation greater than 104, realizing a degree of electronic uniformity previously unattained in InSe thin-film synthesis.

Indium sulfide-based electron-selective contact and dopant-free heterojunction silicon solar cells

Dopant-free carrier-selective contacts have gained attention for application in silicon solar cells because of their simpler preparation process and low-temperature fabrication. However, there were few reports on efficient p-Si solar cells having dopant-free electron contacts. In this study, indium sulfide (In2S3) thin films were successfully deposited by simple thermal evaporation at room temperature and used as dopant-free electron-selective contacts on the front side of p-Si heterojunction solar cells. The changes in crystal structures, optical properties, compositions, and energy-band structures of the In2S3 thin films due to different annealing temperatures were investigated. The champion conversion efficiency of 10.72% was achieved with lightly doped, textured front Czochralski (Cz) p-Si wafers, and a low thermal energy cost. This study demonstrates that In2S3 film is an effective electron-selective contact for silicon solar cells, providing an alternative simple process to the fabrication of dopant-free optoelectronic devices.

Synthesis of indium sulfide photoanode, its characterization and application for degradation of methylene blue and methyl orange

The researches on methylene blue (MB) and methyl orange (MO) destructions were carried out using indium sulfide (In2S3) photoanode in photoelectrocatalytic system. It consisted of In2S3 thin film as an anode synthesized by chemical bath deposition (CBD) on FTO and platinum as a cathode. Characterization with EDX showed the presence of In2S3 with a composition close to In2S3 for 10 min deposition. The In2S3 band gap measurement was obtained 2.49 eV. Photocurrent measurement revealed that In2S3 had n-type semiconductor property. The application of In2S3 thin film as photoanode in a photoelectrocatalytic cell for MB and MO treatments gave degradation’s yields ca. 71 and 55 %, respectively, under illumination with a 20 watt UV lamp, a bias voltage of 0.5 V for 150 min and with sample concentration of 25 mg/L.

Structural and optical properties of In2S3 thin films deposited by sulfurization assisted thermal evaporation method

Indium sulfide (In 2 S 3 ) films were deposited onto soda lime glass by sulfurization assisted thermal evaporation method at different sulfurization temperatures. These films are further annealed for 1 hr at 300 °C. The structural, morphology and optical properties of these films are studied using x-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive x-ray analysis (EDAX), Raman and UV–Visible spectroscopy. Low angle-XRD analysis revealed that all films are polycrystalline in nature and confirmed the formation of only cubic phase of In 2 S 3 . The FE-SEM and EDAX analysis revealed significant change in the film morphology and composition upon sulfurization and annealing temperature. UV–Visible spectroscopy analysis showed that all films have strong absorption in visible region of the spectrum. With increase in sulfurization and annealing temperature the band gap increases and is found in the range 1.57–2.12 eV. However, band gap of In 2 S 3 thin films deposited at different sulfurization temperature are higher than those obtained after annealing of films.

Electrical investigation of sprayed In2S3 film

Indium sulfide thin film has been deposited by spray pyrolysis technique at 340 °C. Structural analysis by XRD and Raman analysis confirm that this sample is polycrystalline, belongs to the β cubic phase and has no secondary phases. The crystallite size is around 32 nm. Morphological study shows that the surface is entirely protected with grains of different sizes and have continuous surface. Electrical properties of In2S3 thin film show that the conductance increases with increasing measurement temperature. The film conduction mechanism can be explained in terms of correlated barrier hopping (CBH) model. Activation energies deduced from relaxation time and conductance is very close which indicate that the relaxation and electrical conduction processes are related to the same origin. Nyquist diagram shows the appearance of semicircles whose radius R (R: resistance) decreases with the increase of temperature. The obtained In2S3 equivalent circuit consisted of R and CPE connected in parallel one to another.

Ultrafast broadband reverse saturation absorption in Al-doped InSe thin films for optical limiting at visible/near-infrared

Abstract Metal-doped InSe has received much attention due to the ultrafast response and strong nonlinearity at high laser fluence. Herein, Al-doped InSe with different doping contents (1.5 W, 2.0 W, and 2.5 W) and pure InSe thin films are fabricated using a magnetron sputtering technology to systematically study their nonlinear absorption behavior at visible/near-infrared. Al-doped InSe (2.5 W) thin film exhibits ultrafast carrier absorption (