A5010461844- Nanowire Synthesis and Applications
- Mercury impact and mitigation studies
- Optical Coatings and Gratings
- Photonic and Optical Devices
- GaN-based semiconductor devices and materials
- Constructed Wetlands for Wastewater Treatment
- Gas Sensing Nanomaterials and Sensors
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor Quantum Structures and Devices
- Silicon Nanostructures and Photoluminescence
- Semiconductor materials and interfaces
- Phosphorus and nutrient management
- Photonic Crystals and Applications
- Advanced Thermoelectric Materials and Devices
- Industrial Gas Emission Control
- Mine drainage and remediation techniques
- Toxic Organic Pollutants Impact
- Wastewater Treatment and Reuse
- Semiconductor materials and devices
- Anodic Oxide Films and Nanostructures
- Quantum Dots Synthesis And Properties
- Thermal properties of materials
- Coagulation and Flocculation Studies
- Air Quality and Health Impacts
- Plasma Applications and Diagnostics
Visvesvaraya National Institute of Technology
2019-2023
Indian Institute of Technology Kanpur
2015-2018
University of Illinois Urbana-Champaign
2011-2017
Periodic high aspect ratio GaAs nanopillars with widths in the range of 500-1000 nm are produced by metal-assisted chemical etching (MacEtch) using n-type (100) substrates and Au catalyst films patterned soft lithography. Depending on etchant concentration temperature, nanowires either vertical or undulating sidewalls formed an etch rate 1-2 μm/min. The realization III-V nanostructure arrays wet can potentially transform fabrication a variety optoelectronic device structures including...
We report the fabrication of degenerately doped silicon (Si) nanowires different aspect ratios using a simple, low-cost and effective technique that involves metal-assisted chemical etching (MacEtch) combined with soft lithography or thermal dewetting metal patterning. demonstrate sub-micron diameter Si nanowire arrays as high 180:1, present challenges in producing solid MacEtch doping level increases both p- n-type Si. systematic reduction porosity these by adjusting solution composition...
We demonstrate GaAs pillar array-based light emitting diodes (LEDs) with axial p-i-n junctions fabricated using a room-temperature metal-assisted chemical etching (MacEtch) method. Variations in vertical etch rates for all three doping types of are investigated as function temperature, oxidant/acid concentration ratio, and dilution the solution. Control over nanopillar morphologies is demonstrated, simply through modification conditions. Optical emission enhancement from MacEtched LED...
Metal-assisted chemical etching (MacEtch) is a simple method that uses metal as the catalyst for anisotropic of semiconductors. However, producing nano-structures using MacEtch from discrete patterns, in contrast to interconnected ones, has been challenging because difficulties keeping features close contact with semiconductor. We report use magnetic field-guided (h-MacEtch) fabricate periodic nanohole arrays silicon-on-insulator (SOI) wafers high reflectance photonic crystal membrane...
Existing theory and data cannot quantify the contribution of phonon drag to Seebeck coefficient (S) in semiconductors at room temperature. We show that this is possible through comparative measurements between nanowires bulk. Phonon boundary scattering completely quenches silicon enabling quantification its S bulk range 25-500 K. The surprisingly large (∼34%) 300 K even doping ∼3 × 10(19) cm(-3). Our results contradict notion negligible degenerate temperatures relevant for thermoelectric...
Metal‐assisted chemical etching (MacEtch) has shown tremendous success as an anisotropic wet method to produce ultrahigh aspect ratio semiconductor nanowire arrays, where a metal mesh pattern serves the catalyst. However, producing vertical via arrays using MacEtch, which requires of discrete disks catalyst, often been challenging because detouring individual catalyst off path while descending, especially at submicron scales. Here, realization ordered, vertical, and high silicon by MacEtch...
We demonstrated removal of Hg<sup>0</sup> vapor by adsorbing it on thiol-impregnated calcium carbonate and assessed the significance temperature thiol mass in removal.
Aluminum is present in significant concentrations water treatment residue (WTR), a waste product obtained during turbidity removal drinking treatment. This study aimed at exploring the potential for recovery of coagulant from WTR using Acidithiobacillus ferroxidans (ATF) and reusing recovered (RC) water. The activity ATF was measured by monitoring pH Al (in %, AlR%). effects two factors (WTR sulfur dose) on were studied central composite design (CCD) response surface methodology (RSM)....
Based on Fano resonance principles in photonic crystals, high performance broadband reflectors can be realized with 100% reflection. Applying an innovative magnetic field guided metal-assisted chemical etching (MacEtch) process, we report here membrane SOI controlled sidewall and reflection around 1550 nm. This work represents the first demonstration of magnetically MacEtch (<i>h</i>-MacEtch) periodic arrays discrete nanoholes sub-micron dimensions. Such process lead to facile formation...
Ordered arrays of GaAs/InGaAs micro and nanopillars are formed by metal-assisted chemical etching (MacEtch). The dependence morphology etch rate upon temperature, etchant composition, doping concentration explored optical characteristics discussed.