SearcharxivSearch

arXiv subjects

Intekhab Alam

Publications and source records attributed to Intekhab Alam.

6 recordsLinked to original sources

Supersonic Microparticle Impact Experiments at Temperatures Approaching 2000 {\deg}C

Experiments at extreme strain rates and temperatures are critical for characterizing materials in high-speed applications. In this study, we develop a laser-driven particle impact platform capable of accelerating microparticles to supersonic velocities and impacting targets heated to temperatures approaching 2000 {\deg}C. The conventional laser-induced particle impact testing (LIPIT) system has been modified to enable high-temperature experiments through the integration of a resistive heating system and the development of a robust launch pad assembly suitable for accelerating particles in high-temperature environments. To eliminate the oxidation of materials at elevated temperatures, an optically accessible portable vacuum chamber has been developed and integrated into the setup. The capabilities of the system are demonstrated through a study of the temperature dependent particle impact cratering behavior of POCO graphite. With this new platform, high-velocity, high-temperature impact experiments can be performed in a controlled environment, supporting the investigation of materials under extreme conditions.

cond-mat.mes-hall

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

Investigating the theoretical performance of Cs$_2$TiBr$_6$-based perovskite solar cell with La-doped BaSnO$_3$ and CuSbS$_2$ as the charge transport layers

A lead-free, completely inorganic, and non-toxic Cs2TiBr6-based double perovskite solar cell (PSC) was simulated via SCAPS 1-D. La-doped BaSnO3 (LBSO) was applied as the electron transport layer (ETL) unprecedentedly in the simulation study of PSCs, while CuSbS2 was utilized as the hole transport layer (HTL). wxAMPS was used to validate the results of SCAPS simulations. Moreover, the first-principle density function theory (DFT) calculations were performed for validating the 1.6 eV bandgap of the Cs2TiBr6 absorber. To enhance the device performance, we analyzed and optimized various parameters of the PSC using SCAPS. The optimum thickness, defect density, and bandgap of the absorber were 1000 nm, 1013 cm-3, and 1.4 eV, respectively. Furthermore, the optimum thickness, hole mobility, and electron affinity of the HTL were 400 nm, 102 cm2V-1s-1, and 4.1 eV, respectively. However, the ETL thickness had a negligible effect on the device's efficiency. The optimized values of doping density for the absorber layer, HTL, and ETL were 1015, 1020, and 1021 cm-3, respectively. Herein, the effect of different HTLs was analyzed by matching up the built-in voltage (Vbi) in respect of the open-circuit voltage (VOC). It was found that the Vbi was directly proportional to the VOC, and CuSbS2 was the champion in terms of efficiency for the PSC. The optimum work function of metal contact and temperature of the PSC were 5.9 eV and 300 K, respectively. After the final optimization, the device achieved an exhilarating PCE of 29.13%.

physics.app-ph

Numerical Simulation of Cs2AgBiBr6-based Perovskite Solar Cell with ZnO Nanorod and P3HT as the Charge Transport Layers

We carried out simulative investigations on a non-toxic, lead-free perovskite solar cell (PSC), where Cs2AgBiBr6, P3HT, ZnO nanorod, and C were utilized as the absorber layer, hole transport layer, electron transport layer, and back contact, respectively. At 600 nm optimum absorber thickness, the device achieved a maximum power conversion efficiency of 4.48%. The PSC operated optimally when the electron affinities were set at 3.3 eV and 4.6 eV for P3HT and ZnO nanorod, respectively. Moreover, the hole mobility and acceptor concentration of P3HT should be weighed during the choosing of appropriate doping additives and doping levels. Besides, the optimum back contact work function and absorber defect density were found to be 5.2 eV and 1E15 cm-3, respectively. We also observed the effect of radiative recombination rates and different charge transport layers on the device's performance. Overall, this study's simulation results will provide insightful guidance towards fabricating an environmentally benign PSC.

cond-mat.mtrl-sci

Effect of Different Device Parameters on Tin Based Perovskite Solar Cell Coupled with In2S3 Electron Transport Layer and CuSCN and Spiro-OMeTAD Alternative Hole Transport Layers for High Efficiency Performance

SCAPS 1-D was used for the simulation of lead-free environmentally benign methylammonium tin-iodide (CH3NH3SnI3) based solar cell. Indium sulphide (In2S3) was utilized as the electron transport layer (ETL) for its high carrier mobility and optimized band structure, unlike traditional titanium oxide (TiO2) ETL. Traditional expensive spiro-OMeTAD (C81H68N4O8) and cheaper cuprous thiocyanate (CuSCN) were utilized alternatively as hole transport layer (HTL) to observe the effect of different HTL on cell performance. We investigated the trend in electrical measurements by altering parameters such as thickness, defect density, valence band (VB) effective density of state and bandgap of the absorber layer, interfacial trap densities and defect density of ETL. At optimum condition, the device revealed the highest efficiency of 18.45% for CuSCN (HTL) and 19.32% for spiro-OMeTAD (HTL) configuration. The effect of working temperature, the wavelength of light and band-to-band radiative recombination rate was also observed for both configurations. All these simulation results will help to fabricate eco-friendly high-efficiency perovskite solar cell by replacing the commonly used toxic lead-based perovskite.

cond-mat.mtrl-sci

Fabrication of zinc oxide/graphene-carbon nanotubes nanocomposite with enhanced dye degradation ability

A comparative study between zinc oxide graphene-carbon nanotubes nanocomposite and ZnO nanoparticles was carried out to investigate their abilities in the degradation of Rhodamine B dye. We utilized the Modified Hummer method to prepare the graphene oxide nanosheet. Moreover, graphene-carbon nanotubes had been synthesized from GO and multi-walled carbon nanotubes with a hydroxyl group. The hydrothermal method was employed to fabricate the zinc oxide graphene-carbon nanotubes nanocomposite from ZnO nanoparticles and graphene-carbon nanotubes. During the characterization by X-ray Diffraction (XRD), all the significant peaks of ZnO and zinc oxide graphene-carbon nanotubes nanocomposite were found in the same phase angle. In addition, the final nanocomposite was also characterized by Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-ray Spectroscopy (EDS). Finally, from the dye degradation test, it was apparent that zinc oxide graphene-carbon nanotubes nanocomposite showed superior dye removal ability compared to the ZnO nanoparticles.

cond-mat.mes-hall