arXiv subjects

M. Khalid Hossain

Publications and source records attributed to M. Khalid Hossain.

12 recordsLinked to original sources

arXiv2022

Study on the hydrogen behavior in Y and Co doped barium-zirconate

Hydrogen release behavior from mixed-perovskite oxide, yttrium and cobalt doped barium-zirconate, BaZr$_{0.955}$Y$_{0.03}$Co$_{0.015}$O$_{3-a}$ (BZYC) exposed to D$_2$ or D$_2$O atmosphere was studied by thermal desorption spectroscopy (TDS) detecting deuterium gas (D$_2$) and heavy water vapor (D$_2$O) separately. The release of hydrogen appeared at around 1000 K. Hydrogen solubility was higher in the BZYC sample exposed to the D$_2$O.

cond-mat.mtrl-sci↗

arXiv2022

Combined DFT, SCAPS-1D, and wxAMPS frameworks for design optimization of efficient Cs2BiAgI6-based perovskite solar cells with different charge transport layers

In this study, combined DFT, SCAPS-1D, and wxAMPS frameworks are used to investigate the optimized designs of Cs2BiAgI6 double perovskite-based solar cells. The first-principle calculation is employed to investigate the structural stability, optical responses, and electronic contribution of the constituent elements in Cs2BiAgI6 absorber material, where SCAPS-1D and wxAMPS simulators are used to scrutinize different configurations of Cs2BiAgI6 solar cells. Here, PCBM, ZnO, TiO2, C60, IGZO, SnO2, WS2, and CeO2 are used as ETL, and Cu2O, CuSCN, CuSbS2, NiO, P3HT, PEDOT: PSS, Spiro-MeOTAD, CuI, CuO, V2O5, CBTS, CFTS are used as HTL, and Au is used as a back contact. About ninety-six combinations of Cs2BiAgI6-based solar cell structures are investigated, in which eight sets of solar cell structures are identified as the most efficient structures. Besides, holistic investigation on the effect of different factors such as the thickness of different layers, series and shunt resistances, temperature, capacitance, Mott-Schottky and generation-recombination rates, and J-V (current-voltage density) and QE (quantum efficiency) characteristics is performed. The results show CBTS as the best HTL for Cs2BiAgI6 with all eight ETLs used in this work, resulting in a power conversion efficiency (PCE) of 19.99%, 21.55%, 21.59%, 17.47%, 20.42%, 21.52%, 14.44%, 21.43% with PCBM, TiO2, ZnO, C60, IGZO, SnO2, CeO2, WS2, respectively. The proposed strategy may pave the way for further design optimization of lead-free double perovskite solar cells.

cond-mat.mtrl-sci↗

arXiv2022

Evaluation of the hydrogen solubility and diffusivity in proton-conducting oxides by converting the PSL values of a tritium imaging plate

Proton-conducting oxides have potential applications in hydrogen sensors, hydrogen pumps, and other electrochemical devices including the tritium purification and recovery systems of nuclear fusion reactors. Although the distribution of hydrogen (H) in such oxide materials is an important aspect, its precise measurement is difficult. In the present study, the hydrogen solubility and diffusivity behavior of BaZr0.9Y0.1O2.95 (BZY), BaZr0.955Y0.03Co0.015O2.97 (BZYC), and CaZr0.9In0.1O2.95 (CZI) were studied using tritiated heavy water vapor i.e., DTO (~2 kPa, tritium (T) = 0.1%) by converting the photostimulated luminescence (PSL) values of the imaging plate (IP). The samples were exposed to DTO vapor at 673 K for 2 h or at 873 K for 1 h. The disc-shaped oxide specimens (diameter ~7.5 mm; thickness ~2.3 mm; theoretical density (TD) > 98 %) were prepared by conventional powder metallurgy. The IP images of the specimen surfaces of all the three materials T-exposed revealed that BZY showed the most uniform T distribution with the highest tritium activity. The cross-sectional T concentration profiles of the cut specimens showed that T diffused deeper into BZY and BZYC than into CZI. The hydrogen solubility and diffusivity in the CZI specimen were lower than that in the BZY and BZYC specimens. This suggested that barium zirconates were more favorable proton conductors than calcium zirconates.

cond-mat.mtrl-sci↗

arXiv2022

First-principles calculations to investigate structural, elastic, electronic, thermodynamic, and thermoelectric properties of CaPd$_3$B$_4$O$_{12}$ (B = Ti, V) perovskite

This study has explored numerous physical properties of CaPd$_3$Ti$_4$O$_{1}$2 (CPTO) and CaPd$_3$V$_4$O$_{12}$ (CPVO) quadruple perovskites employing the density functional theory (DFT) method. The mechanical permanence of these two compounds was observed by the Born stability criteria as well. The band structure of CPTO reveals a 0.88 and 0.46 eV direct narrow band gap while using GGA-mBJ and GGA-PBE potentials, respectively, which is an indication of its fascinating semiconducting nature. The calculated partial density of states indicates the strong hybridization between Pd-4d and O-2p orbital electrons for CPTO, whereas Pd-4d and V-3d-O-2p for CPVO. The study of the chemical bonding nature and electronic charge distribution graph reveals the coexistence of covalent O-V/Pd bonds, ionic O-Ti/Ca bonds, as well as metallic Ti/V-Ti/V bonding for both compounds. The Fermi surface of CPVO ensures a kind of hole as well as electron faces simultaneously, indicating the multifarious band characteristic. The prediction of the static real dielectric function (optical property) of CPTO at zero energy implies its promising dielectric nature. The photoconductivity and absorption coefficient of CPBO display good qualitative compliance with the consequences of band structure computations. The calculated thermodynamic properties manifest the thermodynamical stability for CPBO, whereas phonon dispersions of CPVO exhibit stable phonon dispersion in contrast to slightly unstable phonon dispersion of CPTO. The predicted Debye temperature ($θ_D$) has been utilized to correlate its topical features including thermoelectric behaviors. The studied thermoelectric transport properties of CPTO yielded the Seebeck coefficient (186 V/K), power factor (11.9 Wcm$^{-1}$K$^{-2}$), and figure of merit (ZT) value of about 0.8 at 800 K, indicating that this material could be a promising candidate for thermoelectric applications.

physics.app-ph↗

arXiv2022

Design and numerical investigation of cadmium telluride (CdTe) and iron silicide (FeSi2) based double absorber solar cells to enhance power conversion efficiency

Inorganic CdTe and FeSi2-based solar cells have recently drawn a lot of attention because they offer superior thermal stability and good optoelectronic properties compared to conventional solar cells. In this work, a unique alternative technique is presented by using FeSi2 as a secondary absorber layer and In2S3 as the window layer for improving photovoltaic (PV) performance parameters. Simulating on SCAPS-1D, the proposed double-absorber (Cu/FTO/In2S3/CdTe/FeSi2/Ni) structure is thoroughly examined and analyzed. The window layer thickness, absorber layer thickness, acceptor density (NA), donor density (ND), defect density (Nt), series resistance (RS), and shunt resistance (Rsh) were simulated in detail for optimization of the above configuration to improve PV performance. According to this study, 0.5 um is the optimized thickness for both the CdTe and FeSi2 absorber layers in order to maximize efficiency. Here, the value of the optimum window layer thickness is 50 nm. For using CdTe as a single absorber, the efficiency is achieved by 13.26%. But for using CdTe and FeSi2 as a dual absorber, the efficiency is enhanced and the obtaining value is 27.35%. The other parameters are also improved and the obtaining values for fill factor (FF) are 83.68%, open-circuit voltage (Voc) is 0.6566V, and short circuit current density (JSc) is 49.78 mA/cm2. Furthermore, the proposed model performs good at 300 K operating temperature. The addition of the FeSi2 layer to the cell structure has resulted in a significant quantum efficiency (QE) enhancement because of the rise in solar spectrum absorption at longer wavelengths. The findings of this work offer a promising approach for producing high-performance and reasonably priced CdTe-based solar cells.

physics.app-ph↗

arXiv2022

A Review of Applications, Prospects, and Challenges of Proton-Conducting Zirconates in Electrochemical Hydrogen Devices

In the future, when fossil fuels are exhausted, alternative energy sources will be essential for everyday needs. Hydrogen-based energy can play a vital role in this aspect. This energy is green, clean, and renewable. Elec-trochemical hydrogen devices have been used extensively in nuclear power plants to manage hydrogen-based renewable fuel. Doped zirconate materials are commonly used as an electrolyte in these electrochemical devices. These materials have excellent physical stability and high proton transport numbers, which make them suitable for multiple applications. Doping enhances the physical and electronic properties of zirconate materials and makes them ideal for practical applications. This review highlights the applications of zirconate-based pro-ton-conducting materials in electrochemical cells, particularly in tritium monitors, tritium recovery, hydrogen sensors, and hydrogen pump systems. The central section of this review summarizes recent investigations and provides a comprehensive insight into the various doping schemes, experimental setup, instrumentation, op-timum operating conditions, morphology, composition, and performance of zirconate electrolyte materials. In addition, different challenges that are hindering zirconate materials from achieving their full potential in elec-trochemical hydrogen devices are discussed. Finally, this paper lays out a few pathways for aspirants who wish to undertake research in this field.

physics.app-ph↗

arXiv2022

Effect of various electron and hole transport layers on the performance of CsPbI3-based perovskite solar cells: A numerical investigation in DFT, SCAPS-1D, and wxAMPS frameworks

CsPbI3 has recently received tremendous attention as a possible absorber of perovskite solar cells (PSCs). However, CsPbI3-based PSCs have yet to achieve the high performance of the hybrid PSCs. In this work, we performed a density functional theory (DFT) study using the Cambridge Serial Total Energy Package (CASTEP) code for the cubic CsPbI3 absorber to compare and evaluate its structural, electronic, and optical properties. The calculated electronic band gap (Eg) using the GGA-PBE approach of CASTEP was 1.483 eV for this CsPbI3 absorber. Moreover, the computed density of states (DOS) exhibited the dominant contribution from the Pb-5d orbital, and most charge also accumulated for the Pb atom as seen from the electronic charge density map. Fermi surface calculation showed multiband character, and optical properties were computed to investigate the optical response of CsPbI3. Furthermore, we used IGZO, SnO2, WS2, CeO2, PCBM, TiO2, ZnO, and C60 as the electron transport layers (ETLs), and Cu2O, CuSCN, CuSbS2, Spiro-MeOTAD, V2O5, CBTS, CFTS, P3HT, PEDOT: PSS, NiO, CuO, and CuI as the hole transport layers (HTLs) to identify the best HTL/CsPbI3/ETL combinations using the SCAPS-1D solar cell simulation software. Among 96 device structures, the best-optimized device structure, ITO/TiO2/CsPbI3/CBTS/Au was identified, which exhibited an efficiency of 17.9%. The effect of absorber and ETL thickness, series resistance, shunt resistance, and operating temperature was also evaluated for the six best devices along with their corresponding generation rate, recombination rate, capacitance-voltage, current density-voltage, and quantum efficiency characteristics. The obtained results from SCAPS-1D were also compared with wxAMPS simulation software.

cond-mat.mtrl-sci↗

arXiv2021

Recent progress of fabrication, characterization, and applications of anodic aluminum oxide (AAO) membrane: A review

The progress of membrane technology with the development of membranes with controlled parameters led to porous membranes. These membranes can be formed using different methods and have numerous applications in science and technology. Anodization of aluminum in this aspect is an electro-synthetic process that changes the surface of the metal through oxidation to deliver an anodic oxide layer. This process results in a self-coordinated, exceptional cluster of round and hollow formed pores with controllable pore widths, periodicity, and thickness. After the initial introduction, the paper proceeds with a brief overview of anodizing process. That engages anodic aluminum oxide (AAO) layers to be used as formats in various nanotechnology applications without the necessity for expensive lithographical systems. This review article surveys the current status of the investigation on AAO membranes. A comprehensive analysis is performed on AAO membranes in applications; filtration, sensors, drug delivery, template-assisted growth of various nanostructures. Their multiple usages in nanotechnology have also been discussed to gather nanomaterials and devices or unite them into specific applications, such as nano-electronic gadgets, channel layers, and clinical platforms tissue designing. From this review, the fact that the specified enhancement of properties of AAO can be done by varying geometric parameters of AAO has been highlighted. No review paper focused on a detailed discussion of applications of AAO with prospects and challenges. This review paper represents the formation, properties, applications with objective consideration of the prospects and challenges of AAO applications. The prospects may appeal to researchers to promote the development of unique membranes with functionalization and controlled geometric parameters and check the feasibility of the AAO membranes in nano-devices.

physics.app-ph↗

arXiv2021

Comparative studies of hydrogen dissolution and release behavior in zirconate oxides by TDS and TMAP4 analysis

Proton-conducting oxides are potential materials for electrochemical devices such as fuel cells, hydrogen pumps, hydrogen sensors, and the tritium purification and recovery system in nuclear fusion reactors. The hydrogen concentration in oxide materials is important, but its precise measurement is difficult. In this study, thermal desorption spectroscopy (TDS) was used to investigate hydrogen dissolution and release behavior in proton-conducting oxides, yttrium (Y), and cobalt (Co) doped barium-zirconates in the temperature range of 673-1273 K using deuterium (D2) and heavy water (D2O). Specimens were prepared with conventional powder metallurgy: the powder of three zirconates, BaZr0.9Y0.1O3-a (BZY), BaZr0.955Y0.03Co0.015O3-a (BZYC), and CaZr0.9In0.1O2.95 (CZI) was pressed into discs and fired in the air at 1873 K for 20 h. The densities of the sintered BZY, BZYC, and CZI specimens were 98 percent, 99.7 percent, and 99.5 percent of the theoretical densities respectively. XRD, SEM, and EDX were performed for the structural and morphological analysis of the sintered samples. From TDS measurement, a similar trend of temperature-dependent hydrogen solubility was obtained for all samples compared to the tritium imaging plate (TIP) methods literature data of HT- and DTO-exposed samples. To compare the experimental results of the deuterium desorption profile derived by TDS analysis, the simulation code of the tritium migration analysis program, version 4 (TMAP4) was employed.

physics.app-ph↗

arXiv2021

A comprehensive first principles calculations on (Ba0.82K0.18)(Bi0.53Pb0.47)O3 single-cubic-perovskite superconductor

In this present study, the pseudopotential plane-wave (PP-PW) pathway in the scheme of density functional theory (DFT) is utilized to investigate the various physical properties on (Ba0.82K0.18)(Bi0.53Pb0.47)O3 (BKBPO) single perovskite superconductor. We have analyzed elastic constants and moduli at zero and elevated pressures (up to 25 GPa) as well. We also have investigated the anisotropic nature incorporating both the theoretical indices and graphical representations in 2D and 3D dimensions, which reveals a high level of anisotropy. The flatness of the energy bands near EF is a sign of Van-Hf singularity that might increase the electron pairing and origination of high-TC superconductivity. The computed band structure exhibits its metallic characteristics is confirmed by band overlapping. A band of DOS is formed for the strong hybridization of the constituent elements. The orbital electrons of O-2p contribute most dominantly at EF in contrast to all orbital electrons. The orbital electrons at the EF are higher from both the partial density of states and charge density mapping investigation. The coexistence of the electron and hole-like Fermi sheets exhibits the multi-band nature of BKBPO. On the other hand, Fermi surfaces with flat faces promote transport features and Fermi surface nesting as well. The calculated value of the electron-phonon coupling constant (λ = 1.46) is slightly lower than the isostructural superconductor, which indicates that the studied BKBPO can be treated as a strongly coupled superconductor similar to the reported isostructural perovskite superconductors. Furthermore, the thermodynamic properties have been evaluated and analyzed at elevated temperature and pressure by using harmonic Debye approximation (QHDA).

cond-mat.supr-con↗

arXiv2021

Isotopic effect of proton conductivity in barium-zirconates for various hydrogen-containing atmospheres

Among various perovskite proton conducting oxides, Y-doped BaZrO3 perovskite is a promising material for electrochemical hydrogen devices due to the good chemical stability and higher proton conductivity at higher operating temperatures like 500-800 °C. For the practical application of the functional BaZrO3 proton conductor in the electrochemical hydrogen devices, its necessary to understand the isotopic effect of proton conductivity. To understand the isotopic effect of proton conductivity in the barium zirconates, in this study, the proton conductivity in the Ar, (Ar + 4% H2), (Ar + 4% D2), (Ar + H2O), (Ar + D2O), and O2 atmospheres were measured for two different compositions: BaZr0.9Y0.1O2.95 (BZY), and BaZr0.955Y0.03Co0.015O2.97 (BZYC) in the temperature range from 500 °C to 1000 °C. By comparing the obtained results, a significant difference in sinterability, conductivity, and the isotopic effect was observed due to the co-doping of the Co element in the BaZr1-xYxO3-a proton conductor.

cond-mat.mtrl-sci↗

arXiv2019

Study and analysis the Cu nanoparticle assisted texturization forming low reflective silicon surface for solar cell application

Monocrystalline silicon solar cells with photo-absorbing morphology can amplify light-trapping properties within the absorber layer and help to fabricate cost-effective solar cells. In this paper, the effect of different parameters namely temperature and time of Cu-assisted chemical etching was thoroughly investigated for the optimization of the light absorption properties. P-type monocrystalline wafers were selectively treated with Cu(NO3)2.3H2O:HF:H2O2:DI water solution at 50 deg.C for five different time duration. The entire process was repeated at five different temperatures for 20min as well to study the relation between etching temperature and surface reflectance. Sonication bathing was used for the removal of the deposited Cu atoms from the surface with the variation of time and the effect was examined using energy dispersive spectroscopy (EDS). Field emission scanning electron microscopy (FESEM) and UV/VIS spectroscopy were conducted to study the surface morphology and light absorbance respectively. Inverted shapes almost similar to inverted pyramids or porous surface were found randomly on the surface of the wafer. The effect of temperature was found more significant compared to the effect of time variation. An optimum light reflectance was found at 50 deg.C for 20 min of texturization. Atomic force microscopy (AFM) of the textured sample revealed the average depth of pyramidal shape was about 1.58 micro meter. EDS results showed a proportional relation between time and Cu removal process, and a complete Cu atoms free textured surface after 25 min of sonication bathing. Therefore, a suitable Cu-assisted texturization technique was found, which could enable lowering the photo-reflectance below 1% without any antireflection coating.

physics.app-ph↗