Design Simulation and Fabrication of 3D Electrode for Dielectrophoretic Chip

This paper presents the design, simulation and fabrication of dielectrophoretic chip with integrated nickel 3D electrodes for bioparticle separation. Finite element analysis software COMSOL Multyphysics 4.3 is used to measure the electric field distribution and also the temperature profile inside the microfluidic channel. The temperature rise is found to be 0.5 K. Electric field distribution shows almost uniform electric field on XY plane at different Z axis. Fabrication of 3D nickel electrode is accomplished using electroplating process. 3D sidewall dielectrophoretic chip reduces the electrochemical effect and joule heating effect

Numerical simulation and optimization of lead free CH3NH3SnI3 perovskite solar cell with CuSbS2 as HTL using SCAPS 1D

Perovskite-based solar cells have recently emerged as promising devices in the PV field. Majority of the perovskite material contains lead (Pb) which is toxic in nature which hinder its commercial uses. In this paper, Simulation of a lead-free perovskite solar cell has been discussed where CH3NH3SnI3 is used as an absorber layer. This material is considered due to its low band gap, high visible absorption coefficient, and non-toxic nature. The simulation has been carried out using Solar Cell Capacitance Simulator (SCAPS-1D) tool with the spectrum of AM 1.5 G. The effect of absorber layer thickness, different HTLs (hole transport layer), defect density, doping concentration, working temperature, series resistance, shunt resistance and various back contacts on perovskite solar cell performance are studied with SCAPS-1D. The proposed structure of the optimized device consist of FTO/TiO2/CH3NH3SnI3/CuSbS2/back contact, where titanium dioxide (TiO2), Methyl ammonium tin iodide (CH3NH3SnI3), Copper Antimony Sulfide (CuSbS2) are used as an electron transport layer (ETL), absorber layer, and HTL, respectively. At 300 K, the proposed structure achieves power conversion efficiency (PCE) of 29.74%, open circuit voltage (VOC) of 1.0409 V, short circuit current (JSC) of 33.88 mA/cm2, and fill factor (FF) of 84.31%, respectively

Numerical investigation of CuSbS2 thin film solar cell using SCAPS-1D: enhancement of efficiency on experimental films by defect studies

The study of photovoltaic solar cells has been an exciting field of research because of their environmentally friendly nature. Scientists are continuously searching for new methods to develop solar cells that are highly efficient and cost-effective. One promising option is the use of Copper Antimony Sulphide (CuSbS _2 ) based ternary compound semiconductor in ultrathin film photovoltaic cells. This material has a high absorption coefficient, low cost, and is readily available in the earth’s crust. These characteristics make it an ideal candidate for use as a thin-film absorber layer in solar cells. In this work, FTO/CdS/In _2 S _3 /CuSbS _2 /Spiro-OMeTAD/Au device is proposed to improve the efficiency of experimentally designed CuSbS _2 -based thin film solar cells using numerical modeling. Device simulation was carried out using SCAPS-1D software, and the illumination spectrum used for this optimization was 1.5 AM. The simulated results from SCAPS-1D were compared to the experimental data. After optimizing the device parameters all the electrical parameters of the solar cell were improved. The optimized CuSbS _2 -based device shows power conversion efficiency (PCE) of 21.11% with short circuit current density (J _sc ) of 20.96 mA cm ^−2 , open circuit voltage (V _oc ) of 1.23 V, and fill factor (FF) of 81.84%. Based on the simulation results, it is possible to increase the performance of the device by varying different parameters such as the defect density of each layer, interfacial defect density, thickness, and doping concentration

Formation of micro structured doped and undoped hydrogenated silicon thin films

The microcrystalline hydrogenated-silicon (mu c-Si: H) (also called polymorphous silicon) consisting a two-phase mixture of amorphous and structured silicon is being used for electronic or optoelectronic based thin-film devices. The pc-Si: H thin films are deposited using radio frequency (13.56 MHz) Plasma Enhanced Chemical Vapour Deposition (RF-PECVD) by varying doping gases (diborane (B2H6) and phosphine (PH3)) flow and hydrogen-silane dilution ratio (R = H-2/SiH4) to optimize the crystalline fraction and electrical conductivity. Micro-Raman spectroscopy is used to investigate these effect on the transition fraction regime from amorphous into micro-structured silicon. Qualitative and quantitative properties have been studied by deconvolution of the micro Raman spectra which allows to determine the crystalline fraction in the film and also some investigation regarding the correlation between electrical and structural properties are presented for different annealing temperature (from 300 to 550 degrees C) and various film thickness ranges (10-100 nm). In this work, we present the characterization of thin films (both doped and undoped) deposited at the temperature of 250 degrees C on quartz substrate after annealed at 550 degrees C in N-2-ambient, as a result crystallinity percentage up to 90% for p-type, 96% for n-type and 80% for undoped films are achieved. A detailed characterization of the microcrystalline silicon (mu c-Si: H) has been demonstrated in this paper: structural properties through Raman spectroscopy, electrical properties through Four-point probe station and optical properties using Ellipsometer

Temperature dependent growth of Cu2SnS3 thin films using ultrasonic spray pyrolysis for solar cell absorber layer and photocatalytic application

Ternary chalcogenide Cu2SnS3 (CTS) thin films are deposited on glass substrates using low cost ultrasonic spray pyrolysis (USP) technique by varying substrate temperatures 300 degrees C to 550 degrees C. Crystal structure of CTS thin film is found to change its phase from amorphous to tetragonal phase with increase in substrate temperature. Properties of as-deposited Cu2SnS3 thin films are studied using various characterization techniques. X-ray powder diffraction (XRD) studies confirm the formation of Cu2SnS3 tetragonal phase with orientation along (112) plane with increase in substrate temperature. Raman analysis revealed the formation of binary phase at 550 degrees C substrate temperature. Increase in substrate temperature resulted in stoichiometric nature of Cu2SnS3 films at 500 degrees C. The absorption coefficient of CTS films is found to be similar to 10(5) cm(-1) with band gap ranging from 1.35 eV to 1.48 eV. Electrical properties of CTS films exhibited p type conductivity with carrier concentration of the order of 10 21 cm(-3). The resistivity of the CTS films is found to vary from 1.5 x 10(-3) to 3.2 x 10(-3) Omega-cm. Photocatalytic effect of optimized Cu2SnS3 thin film under visible light (300 W) is examined with methylene blue (MB) dye and similar to 90% MB is degraded under 3 hours visible light irradiation. The above properties indicate that Cu2SnS3 is a potential candidate to be used for solar cell absorber layer and photocatalytic activity

Molybdenum Microheaters for MEMS-Based Gas Sensor Applications: Fabrication, Electro-Thermo-Mechanical and Response Characterization

In this paper, we present the fabrication and characterization of molybdenum microheaters for high-temperature gas sensing applications. The surface morphology of dc magnetron sputtered molybdenum thin films was characterized by scanning electron microscopy and atomic force microscopy. The suspended membrane microheater consumed 104 mW to reach a maximum temperature of 800 degrees C and showed an absolute thermal resistance of 7.2 degrees C/mW. Thermal distribution patterns over the active heating area were recorded using FLIR camera. It showed a temperature gradient of 1.18 % from the center of the microheater to its periphery. The thermal and mechanical stabilities of the microheater were analyzed, and its membrane failure at higher operating temperatures was prevented. The microheater membrane deformation at different temperatures was characterized using optical profilometer, and its maximum value was found to be 16.25 mu m at 800 degrees C. The microheater response to a pulse, continuous pulse train, and constant dc voltages was characterized. Its response and recovery times are in the order of 19 and 34 ms, respectively. It showed a stable temperature with a negligible resistance drift (0.96%) over a period of 600 h. The TiO2 thin film integrated molybdenum microhotplate-based MEMS gas sensor response for CO (5000 ppb) was measured at different operating temperatures (300 degrees C-700 degrees C)