scholarly journals Enhancing the stability and crystallinity of CsPbIBr2 through antisolvent engineering

Author(s):  
Alexander W. Stewart ◽  
Amal Bouich ◽  
Bernabé Marí Soucase

AbstractAll inorganic lead-based perovskites containing bromine-iodine alloys, such as CsPbIBr2, have arisen as one of the most attractive candidates for absorber layers in solar cells. That said, there remains a large gap when it comes to film and crystal quality between the inorganic and hybrid perovskites. In this work, antisolvent engineering is employed as a simple and reproducible method for improving CsPbIBr2 thin films. We found that both the antisolvent used and the conditions under which it was applied have a measurable impact on both the quality and stability of the final product. We arrived at this conclusion by characterising the samples using scanning electron microscopy, X-ray diffraction, UV–visible and photoluminescence measurements, as well as employing a novel system to quantify stability. Our findings, and the application of our novel method for quantifying stability, demonstrate the ability to significantly enhance CsPbIBr2 samples, produced via a static one-step spin coating method, by applying isopropanol 10 s after commencing the spin programme. The antisolvent quenched CsPbIBr2 films demonstrate both improved crystallinity and an extended lifespan.

2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Julia Marí-Guaita ◽  
Amal Bouich ◽  
Bernabé Marí

In this work, FAPbI3 thin films with different antisolvents (toluene, diethyl ether and chlorobenzene) were successfully elaborated by the spin coating technique to study the influence of the different antisolvents in the films. The crystal structure, surface morphology and optical properties were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) photoluminescence and UV–visible spectrometry. According to XRD, the crystalline structure of FAPbI3 was found in the orientation of the (110) plane, and it is observed that the type of antisolvent content in the absorber layer plays an important role in the growth and stabilization of the film. Here, chlorobenzene leads to a smooth and homogenous surface, a large grain size and a pinhole-free perovskite film. Additionally, the optical analysis revealed that the band gap is in the range from 1.55 to 1.57 eV. Furthermore, in an approximately 60% humidity environment and after two weeks, the stability and absorption of FaPbI3 showed low degradation.


2015 ◽  
Vol 35 ◽  
pp. 21-26 ◽  
Author(s):  
Susmita Das ◽  
Vimal Chandra Srivastava

Metal oxide nanocomposite (ZnO-CuO) was successfully synthesized by one step homogeneous coprecipitation method and further characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron micrograph (SEM), X-ray diffraction analysis (XRD) and UV-visible diffuse reflectance spectra. XRD analysis exhibited presence of pure copper oxide and zinc oxide within the nanocomposite. SEM analysis indicated that the ZnO-CuO nanocomposite was consisted of flower shaped ZnO along with leaf shaped CuO. Photocatalytic activity of nanocomposite was evaluated in terms of degradation of methylene blue (MB) dye solution under ultra-violet radiation. Results showed that the photocatalytic efficiency of ZnO-CuO nanocomposite was higher than its individual pure oxides (ZnO or CuO).


2016 ◽  
Vol 5 (5) ◽  
Author(s):  
Phuong Phong Nguyen Thi ◽  
Dai Hai Nguyen

AbstractWe report star-shaped silver@gold (Ag@Au) nanoparticles (NPs) in gelatin suspensions for the purpose of enhancing the stability of Ag@Au NPs. In this case, Ag NPs were designed as nucleating agents, whereas gelatin was used as a protecting agent for Au development. Especially, variable gelatin concentrations were also prepared to explore its ability to increase the stability of Ag@Au NPs. The obtained samples were then characterized by UV-visible spectroscopy, transmission electron spectroscopy (TEM), X-ray diffraction, and Fourier transform infrared spectroscopy. The maximum absorption wavelength of all samples (566–580 nm) indicated that branched Ag@Au@gelatin NPs were successfully synthesized. In addition, our TEM results revealed that the size of branched Ag@Au@gelatin NPs was found to be between 20 and 45 nm as influenced by the component ratio and the pH value. These results can provide valuable insights into the improvement of Ag@Au NP stability in the presence of gelatin.


2018 ◽  
Vol 273 ◽  
pp. 140-145 ◽  
Author(s):  
Dewi Suriyani Che Halin ◽  
Norsuria Mahmed ◽  
Mohd Arif Anuar Mohd Salleh ◽  
A.N. Mohd Sakeri ◽  
Kamrosni Abdul Razak

Ag/TiO2thin films were prepared via sol-gel spin coating method. Structural, surface morphology and optical properties were investigated with the addition of two different amount of silver (Ag). X-ray diffraction pattern shows the sample with pure TiO2, the only phase presence was brookite TiO2. When the Ag content added into the solution, the phase existed for the samples with TiO2doped 0.5g Ag and TiO2doped 1.0g Ag were anatase TiO2with no peak corresponds to Ag phase. The surface morphology of film was characterized by scanning electron microscopy (SEM). The films were annealed at 450 °C and it shows non-uniform films. The films have a large flaky and cracks film which was attributed to surface tension between the film and the air during the drying process. When the solution of sol was added with Ag content, it shows the porous structure with flaky-crack films. With the increasing of the Ag content from 0.5g to 1.0g, the structure is more porous and it is good for the photocatalytic activity. The UV-Vis spectra shows that the film exhibits a low absorbance which was due to the substrate is inhomogeneously covered by the flaky-crack films.


Author(s):  
Feifei Luo ◽  
Liuxia Ruan ◽  
Junwei Tong ◽  
Yanzhao Wu ◽  
Caixiang Sun ◽  
...  

In this study, Yttrium-doped CH3NH3PbI3 (Y-MAPbI3) and pure CH3NH3PbI3 (MAPbI3) perovskite films have been fabricated using a one-step solution spin coating method in a glove box. The X-ray diffractometer and...


2020 ◽  
Vol 32 (11) ◽  
pp. 2722-2730
Author(s):  
K.R. Venugopala Reddy ◽  
N.Y. Praveenkumar ◽  
Mounesh ◽  
T.M. Sharanakumar ◽  
Sangappa K. Ganiger

A novel method for the fabrication of tetrasulfanilamide cobalt(II) phthalocyanine (CoTSPC) was developed and the synthesized product was characterized using various techniques namely UV-visible, infrared and X-ray diffraction spectroscopic and thermal gravimetric analysis. An electrode with glassy carbon was modified on CoTSPC with an rGO composite. The effect of experimental parameters, such as precipitation agent, precursor concentration, reaction time and stabilizing agent, was systematically studied to investigate possible CoTSPC formation. The electrochemical properties of prepared CoTSPC/rGO/GCE were explored through cyclic voltammetry (CV) by using a three-electrode system. The results showed that the specific capacitances and sizes of the fabricated compounds are related. Due to a large surface area, within an operated voltage range of −0.2 to 0.4 V, synthesized CoTSPC/rGO/GCE exhibited an excellent long-cycle life and the highest capacitance (157 F g−1), thereby indicating that fabricated CoTSPC/rGO/GCE can be used as an outstanding electrode material in supercapacitors.


2019 ◽  
Vol 15 (33) ◽  
pp. 40-48
Author(s):  
Atyaf H. Kadhum

The effect of heat treatment on the optical properties of the bulk heterojunction blend nickel (II) phthalocyanine tetrasulfonic acid tetrasodium salt and Tris (8-hydroxyquinolinato) Aluminum (NiPcTs/Alq3) thin films which prepared by spin coating was described in this study. The films coated on a glass substrate with speed of 1500 rpm for 1.5 min and treated with different annealing temperature (373, 423 and 473) K. The samples characterized using UV-Vis, X ray diffraction and Fourier transform Infrared (FTIR) spectra, XRD patterns indicated the presence of amorphous and polycrystalline blend (NiPcTs/Alq3). The results of UV visible shows that the band gap increase with increasing the annealing temperature up to 373 K and decreases with increase the annealing temperature to (423, 473)K respectively.


2020 ◽  
Vol 19 (1) ◽  
pp. 87-93
Author(s):  
Gerardo Gordillo-Guzmán ◽  
Ophyr Virgüez-Amaya ◽  
Camilo Otálora-Bastidas ◽  
Clara Calderón-Triana ◽  
César Quiñones-Segura

This work report results concerning the effect that the substitution of the methylammonium cation by the formamidinium cation causes on the properties of FAx(MA1-x)PbI3films synthesized by spin coating in one step. For that, it was conducted a study to establish the influence of the composition of the FAx(MA1-x)PbI3films on their optical, structural and morphological properties, determined through spectral transmittance, atomic force microscopy and X-ray diffraction measurements. Correlating parameters of synthesis with results of the study of properties performed, we were able to get conditions to grow FAx(MA1-x)PbI3films with improved optical gap, microstructure and morphology, what allows to think that this compound is suitable to be used as the active layer in hybrid solar cells.


Molekul ◽  
2008 ◽  
Vol 3 (1) ◽  
pp. 48
Author(s):  
Bilalodin Bilalodin

The growth of PbTiO3 ferroelectric thin films have successfully done. Thin films were made from bulk (powder) PbTiO3 dissolved in methanol solution. The condensation was mixed during 1 hour to get homogeneous condensation. Thin films were grown above corning substrates by spin coating method. Optimation was done by various of annealing temperature. The physical properties of thin films were characterized by Energi Dispersive X-Ray Spectroscopy (EDS), X-Ray Diffraction (XRD), Scanning and Electron Microscopy (SEM). EDS measurement showed that the stoichiometry composition ratio of Pb/Ti is 1/1.26 at annealing temperature 600oC and 1/1.29 at annealing temperature 700oC. The result of XRD pattern showed that crystal structure of PbTiO3 thin films are tetragonal. The calculated lattice parameters ontained from Chohen Method are a=b= 3.873 Å dan c= 4.130Å. The result of SEM PbTiO3 thin film showed that thin film has globular grain size.


2014 ◽  
Vol 881-883 ◽  
pp. 901-904 ◽  
Author(s):  
Jing Zhang ◽  
Hui Hui Zhu ◽  
Kai Chen Lei ◽  
Heng Quan

WO3doping TiO2composites with nanocarbon are prepared by sol-gel and hydrothermal, and the composites are studied by X-ray diffraction (XRD), UV-visible light scanning. The photocatalytic degradation effects of different conditions on the direct scarlet 4BS solution has been Investigated. The results show that doped WO3does not change the main structure of TiO2, but affect its crystalline properties. When WO3doping amount is 3.0 mol%, the crystallinity of composite reaches maximum value. The introduction of nanocarbon can improve the crystallinity of composite when the molar ratio of WO3doping is 3.0%, the photocatalytic activity is the highest, nanocarbon as a carrier can increase the photocatalyst adsorption capacity to achieve the objective of improving the photocatalytic efficiency when WO3and nanocarbon doped TiO2, the stability of the composite about catalytic activity is excellent.


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