scholarly journals From radical to triradical thin film processes: the Blatter radical derivatives

2021 ◽  
Author(s):  
Arrigo Calzolari ◽  
Andrzej Rajca ◽  
Maria Benedetta Casu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Evaporation ◽  
Controlled Environment

We demonstrate the possibility to evaporate Blatter radical derivatives in a controlled environment obtaining thin films that preserve the (poly)radical magnetic character. However, their thermal evaporation is challenging. We analyse...

Structural Properties of PbI2 Thin Film

2014 ◽  
Vol 879 ◽  
pp. 175-179 ◽  
Author(s):  
Safaa I. Mohammed ◽  
Naser Mahmoud Ahmed ◽  
Y. Al-Douri ◽  
U. Hashim
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Structural Analysis ◽  
Film Thickness ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Lead Iodide ◽  
Thermal Evaporation Method ◽  
Growth Orientation

Lead iodide (PbI2) thin films were successfully prepared by thermal evaporation method on a glass substrate at room temperature. The structural analysis of these films was done by XRD. The results revealed that the crystallite size increases when increasing the film thickness and annealing temperature. In addition, the preferred growth orientation was 001 for all the samples.

scholarly journals Highly Uniform Large-Area (100 cm2) Perovskite CH3NH3PbI3 Thin-Films Prepared by Single-Source Thermal Evaporation

Coatings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 256 ◽  
Author(s):  
Guangxing Liang ◽  
Huabin Lan ◽  
Ping Fan ◽  
Chunfeng Lan ◽  
Zhuanghao Zheng ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solar Cell ◽  
Thermal Evaporation ◽  
Perovskite Solar Cell ◽  
Stoichiometric Ratio ◽  
Single Source ◽  
Large Area ◽  
Highly Uniform ◽  
The Ideal

In this work, we report the reproducible preparation method of highly uniform large-area perovskite CH3NH3PbI3 thin films by scalable single-source thermal evaporation with the area of 100 cm2. The microstructural and optical properties of large-area CH3NH3PbI3 thin films were investigated. The dense, uniform, smooth, high crystallinity of large-area perovskite thin film was obtained. The element ratio of Pb/I was close to the ideal stoichiometric ratio of CH3NH3PbI3 thin film. These films show a favorable bandgap of 1.58 eV, long and balanced carrier-diffusion lengths. The CH3NH3PbI3 thin film perovskite solar cell shows a stable efficiency of 7.73% with almost no hysteresis, indicating a single-source thermal evaporation that is suitable for a large area perovskite solar cell.

scholarly journals Nanocomposite Thin Film TiO2/CdS Electrodes Prepared by Thermal Evaporation Process for Photovoltaic Applications

2011 ◽  
Vol 21 (1) ◽  
pp. 57 ◽  
Author(s):  
Dang Tran Chien ◽  
Pham Duy Long ◽  
Pham Van Hoi ◽  
Le Ha Chi
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Evaporation ◽  
Pure Tio2 ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
Cds Thin Film ◽  
Photovoltaic Applications ◽  
Evaporation Technique ◽  
Beam Deposition

The incorporation of cadmium sulfide (CdS) into TiO2 nanoparticle thin films was investigated. The nanoparticle TiO2 thin film onto an indium doped–tin oxide (ITO) substrate was deposited by Electron Beam Deposition (EBD) combined with thermal process. Then a CdS thin film was vacuum-deposited onto the pre-deposited TiO2 film by a thermal evaporation technique. The obtained TiO2/CdS was characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM). The TiO2/CdS nanocomposite film was used in a photo-electrochemical (PEC) cell as a working electrode and a platinum electrode as a counter electrode. The electrolyte solution contains 1 M KCl and 0.1M Na2S. The results show that the cell with TiO2/CdS composite film electrode has significantly improved photoelectric capability in comparison with that of the pure TiO2 thin films.

scholarly journals Inorganic and Lead-free CsBi3I10 Thin Film Solar cell Prepared by Single-source Thermal Evaporation

2021 ◽  
Author(s):  
Huabin Lan ◽  
Xingye Chen ◽  
Ping Fan ◽  
Guangxing Liang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solar Cells ◽  
Band Gap ◽  
Thermal Evaporation ◽  
Perovskite Solar Cells ◽  
Lead Free ◽  
Single Source ◽  
Thermal Evaporation Method ◽  
Inorganic Lead

Abstract All inorganic lead-free halide perovskites have attracted much attention due to their non-toxic and good band gap. In this paper, we first prepared all inorganic lead-free perovskite CsBi3I10 thin films by single source thermal evaporation deposition. The results show that CsBi3I10 thin films prepared by single source thermal evaporation have layered structure, high purity hexagonal phase and high crystallinity, which are consistent with the theoretical calculation results. The surface of the thin film was compact and uniform, and had high homology with the crystal structure of the evaporation source material. After annealing, the crystallinity of the film was further improved. The band gap of the CsBi3I10 thin film calculated was 1.83 eV, Perovskite solar cells based on CsBi3I10 thin films exhibit an efficiency of up to 0.84%. These results indicate that the proposed single source thermal evaporation method has the potential to prepare high efficiency inorganic lead-free perovskite solar cells.

scholarly journals Single-Source Thermal Evaporation Growth and the Tuning Surface Passivation Layer Thickness Effect in Enhanced Amplified Spontaneous Emission Properties of CsPb(Br0.5Cl0.5)3 Perovskite Films

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2953
Author(s):  
Saif M. H. Qaid ◽  
Hamid M. Ghaithan ◽  
Bandar Ali Al-Asbahi ◽  
Abdullah S. Aldwayyan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Layer Thickness ◽  
Spontaneous Emission ◽  
Surface Passivation ◽  
Thermal Evaporation ◽  
Amplified Spontaneous Emission ◽  
Passivation Layer ◽  
Single Source ◽  
High Quality

High-quality inorganic cesium lead halide perovskite CsPb(Br0.5Cl0.5)3 thin films were successfully achieved through evaporation of the precursors and deposition sequentially by a single-source thermal evaporation system. The different melting points of the precursors were enabled us to evaporate precursors one by one in one trip. The resulting films through its fabrication were smooth and pinhole-free. Furthermore, this technique enabled complete surface coverage by high-quality perovskite crystallization and more moisture stability oppositely of that produce by solution-processed. Then the perovskite films were encapsulated by evaporated a polymethyl methacrylate (PMMA) polymer as a specialized surface passivation approach with various thicknesses. The blue emission, high photoluminescence quantum yield (PLQY), stable, and low threshold of amplified spontaneous emission (ASE) properties of CsPb(Br0.5Cl0.5)3 films in the bulk structure at room temperature were achieved. The effects of the surface-passivation layer and its thickness on the optical response were examined. Detailed analysis of the dependence of ASE properties on the surface passivation layer thickness was performed, and it was determined this achieves performance optimization. The ASE characteristics of bare perovskite thin film were influenced by the incorporation of the PMMA with various thicknesses. The improvement to the surface layer of perovskite thin films compared to that of the bare perovskite thin film was attributed to the combination of thermal evaporation deposition and surface encapsulation. The best results were achieved when using a low PMMA thickness up to 100 nm and reducing the ASE threshold by ~11 μJ/cm2 when compared with free-encapsulation and by ~13 μJ/cm2 when encapsulation occurs at 200 nm or thicker. Compared to the bare CsPb(Br0.5Cl0.5)3, ASE reduced 1.1 times when the PMMA thickness was 100 nm.

Sb2S3/SnSe thin film solar cells by thermal evaporation

2014 ◽  
Vol 1670 ◽  
Author(s):  
José Escorcia-García ◽  
Enue Barrios-Salgado ◽  
M.T.S. Nair ◽  
P.K. Nair
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solar Cell ◽  
Thermal Evaporation ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Glass Substrates ◽  
Cell Structures

ABSTRACTWe report a stable CdS/Sb2S3/SnSe heterojunction thin film solar cell deposited on SnO2:F (FTO) – coated glass substrates. Thermal evaporation at 10-5 Torr with substrate temperature of 400 °C was used to deposit Sb2S3 and SnSe thin films of 450 nm and 160 nm, respectively. Thin film Sb2S3 has an optical band gap (Eg) of 1.48 eV and photoconductivity (σp) of 4x10-7 Ω-1 cm-1 and thin film SnSe has an Eg of 1.28 eV and σp of 2 Ω-1 cm-1. The chemically deposited CdS thin film heated at 400 °C shows an Eg of 2.34 eV and σp of 0.1 Ω-1 cm-1. Stabilized solar cell structures with these thin films, FTO/CdS/Sb2S3/SnSe/C-Ag, showed open circuit voltage (Voc) of 0.60 V, short circuit current density (Jsc) of 5.51 mA/cm2 and power conversion efficiency (η) of 0.96% with a fill factor FF of 0.29. In the absence of the SnSe layer, Jsc decreases to 4.77 mA/cm2.

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

1991 ◽  
Vol 49 ◽  
pp. 1068-1069
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Ablation Process ◽  
Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 264-265
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Compound Semiconductors ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Metastable Alloys ◽  
Lower Voltage

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.

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