Indian Institute of Technology Hyderabad (IITH) is a premier institute of science and technology established in 2008. IITH has been consistently ranked in the&nbsp;<a href="https://iith.ac.in/reports/" rel="noopener noreferrer">top 10 institutes</a>&nbsp;in India for Engineering&nbsp;<a href="https://www.nirfindia.org/2021/EngineeringRanking.html" rel="noopener noreferrer" target="_blank">according to NIRF</a>&nbsp;making it one of the most coveted schools for science and technology in the country.

IITH offers&nbsp;<a href="https://iith.ac.in/academics/under-graduate/">undergraduate programs</a>&nbsp;in all the classical engineering disciplines, applied sciences, design, as well as several modern interdisciplinary areas. Students are given a flexibility to explore a broad set of areas, and potentially pursue a minor or double major in a discipline that is not their own. Students who wish to seek a deeper understanding of their own discipline are strongly encouraged to get involved in cutting-edge research with the help of a faculty to mentor them, and earn an Honors in their own field.

The very foundation of IIT Hyderabad is based on&nbsp;<a href="https://iith.ac.in/research/">research and innovation</a>. The vibrant research culture is evident from the number of patents and publications that IITH produces consistently every year. IITH offers&nbsp;<a href="https://iith.ac.in/academics/programmes-offered/">graduate programs</a>&nbsp;at both a masters, and a doctoral level, in several diverse areas. There are separate programs for technology, design, science, and liberal arts. The&nbsp;<a href="https://iith.ac.in/academics/post-graduate/">MTech program</a>&nbsp;is offered in various modes and durations to cater to the ever-growing need of postgraduate level professionals in the country.

IITH encourages and supports&nbsp;<a href="https://iic-iith.netlify.app/index.html" rel="noopener noreferrer" target="_blank">innovation and entrepreneurship</a>&nbsp;at every stage. The minor program in entrepreneurship is open to all students of IITH, and many of the courses are offered by industrialists who are entrepreneurs themselves. There are various&nbsp;<a href="https://iith.ac.in/research/centres-incubators/">innovation centers and incubators</a>&nbsp;that promote entrepreneurship and help mentor young innovators. IITH has been very successful in building tie-ups with leading academic institutions around the globe.

IITH enjoys a very special relationship with Japanese universities and industries that goes beyond academic and research collaborations. In fact, some of the iconic buildings in IITH campus will carry the signature of Japanese architecture.

IITH creates a unique holistic ecosystem for education that offers interactive learning, a very flexible academic structure, cutting-edge research, strong industry collaboration, and entrepreneurship. This is an environment which enables students and faculty to translate their dreams into realities.

IIT Hyderabad

The fabrication of high performance Schottky barrier diodes (SBDs) between silicon and two different types of conductive carbon films is reported. The diodes are fabricated by simply spin coating and annealing of photoresist films (PPF) or by the chemical vapour deposition of pyrolytic carbon (PyC) onto n-type silicon wafers. After patterning with a metal hardmask and structural transfer a defined diode interface has achieved. The current-voltage characteristics of the SBDs were recorded in ambient. Diode parameters including the ideality factor n, the barrier height φB and the series resistance RS were extracted using an extended thermionic emission theory and the Norde function. The ideality factors were n=1.25 for the PPF/n-Si diodes and n=1.45 for the PyC/n-Si diodes. The values are close to those of commercial products and therefore, these highly durable and easily fabricated diodes may prove to be commercially viable. Moreover, the diode characteristics can be used to evaluate the electrical properties of thin carbon films. © 2012 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.

World University root node

Department of Electrical Engineering

Physica Status Solidi (B) Basic Research

Investigation of carbon-silicon Schottky barrier diodes

The advances in the use of a remote plasma in combination with a rapid radiative reactor in plasma-enhanced (PE) CVD is presented here. The characteristics and parameters of this system are fully analyzed and compared with conventional CVD growth methods. Growth of multi- and single-walled carbon nanotubes (CNTs) at low temperatures with high quality and reproducibility has been achieved in this way. Further, a new catalytic system, which gives dense multi-wall CNTs on metal substrates, is presented. The growth of both MWNTs and SWNTs by remote plasma assisted CVD in a purpose built rapid ramping reactor is presented. The reactor allows for highly reproducible growth, with uniform temperature and plasma conditions and fast sample exchange. The SWNTs grown are of a very high purity and have a repeatable distribution of small diameters. Further, growth of dense aligned MWNT forests on conducting substrates is demonstrated. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical Vapor Deposition

Remote plasma-assisted CVD growth of carbon nanotubes in an optimised rapid thermal reactor

Graphene exhibits exciting properties which make it an appealing candidate for use in electronic devices. Reliable processes for device fabrication are crucial prerequisites for this. We developed a large area of CVD synthesis and transfer of graphene films. With patterning of these graphene layers using standard photoresist masks, we are able to produce arrays of gated graphene devices with four point contacts. The etching and lift off process poses problems because of delamination and contamination due to polymer residues when using standard resists. We introduce a metal etch mask which minimises these problems. The high quality of graphene is shown by Raman and XPS spectroscopy as well as electrical measurements. The process is of high value for applications, as it improves the processability of graphene using high-throughput lithography and etching techniques. © 2011 Kumar et al.

Fulltext

Nanoscale Research Letters

Reliable processing of graphene using metal etchmasks

ZnS nanotetrapods were investigated by atom-resolved microscopy characterization and quantitative simulation. The octahedron core enclosed with Zn- and S-terminated surfaces was verified. Four hexaprism-shaped arms were selectively grown from Zn-terminated surfaces of the core by alternately stacking zinc blende and wurtzite structures. The stacking order change at the core/arm interface is significant to activate the arm growth. The anisotropic growth mechanism was proposed and further proved by the synthesis of ZnS nanoparticles and nanobelts. © 2011 American Chemical Society.

Nano Letters

Atom-resolved evidence of anisotropic growth in ZnS nanotetrapods

The magnetoresistance (MR) of Fe3 O4 -graphene- Fe3 O4 junctions has been experimentally studied at different temperatures. It is found that a barrier exists at the Fe3 O4 /graphene interface. The existence of the interfacial barrier was further confirmed by the nonlinear I-V characteristics and nonmetallic temperature dependence of the interfacial resistance. Moreover, spin dependent transport at the interfaces contributes -1.6% MR to the whole device at room temperature and can be regulated by an external electric field. © 2011 American Institute of Physics.

Applied Physics Letters

Magnetoresistance of Fe3 O4 -graphene- Fe3 O4 junctions

In this article we map out the thickness dependence of the resistivity of individual graphene strips, from single layer graphene through to the formation of graphitic structures. We report exceptionally low resistivity values for single strips and demonstrate that the resistivity distribution for single strips is anomalously narrow when compared to bi- and trilayer graphene, consistent with the unique electronic properties of single graphene layers. In agreement with theoretical predictions, we show that the transition to bulklike resistivities occurs at seven to eight layers of graphene. Moreover, we demonstrate that the contact resistance between graphene flakes in a graphene network scales with the flake thickness and the implications for transparent conductor applications are discussed. © 2011 American Chemical Society.

Nanoscale mapping of electrical resistivity and connectivity in graphene strips and networks

Suspended poly(methyl methacrylate) (PMMA)/graphene microstamps can be site-specifically printed to any targeted position using a micromanipulator. The surface-enhanced Raman spectrum, gate-voltage-dependent conductance, half-integer quantum Hall effect, and electrical interconnection are investigated. Advantages of the technique include precise positioning, avoiding extrinsic doping effect, maintaining the graphene quality, improving the efficiency of chemical vapor deposition (CVD) grown graphene deployment, and convenient device repair. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advanced Materials

Site-specific transfer-printing of individual graphene microscale patterns to arbitrary surfaces

The remarkable properties of graphene have potential for numerous applications; however, their exploitation depends on its reliable production. The chemical vapour deposition (CVD) growth of graphene on metal surfaces has become one of the most promising strategies for the production of high quality graphene in a scaleable manner. Here, we discuss graphene growth on nickel (Ni) and copper (Cu) directly from both gaseous hydrocarbons and solid carbon precursors. Further, we discuss in detail the transfer of graphene films to insulating substrates, by direct and polymer supported transfer methods. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CVD growth and processing of graphene for electronic applications

A gas phase controlled graphene synthesis resembling a CVD process that does not critically depend on cooling rates is reported. The controllable catalytic CVD permits high quality large-area graphene formation with deft control over the thickness from monolayers to thick graphitic structures at temperatures as low as 750 °C. © The Royal Society of Chemistry 2010.

Chemical Communications

Gas phase controlled deposition of high quality large-area graphene films

Ultrathin conductive carbon layers (UCCLs) were created by spin coating resists and subsequently converting them to conductive films by pyrolysis. Homogeneous layers as thin as 3 nm with nearly atomically smooth surfaces could be obtained. Layer characterization was carried out with the help of atomic force microscopy, profilometry, four-point probe measurements, Raman spectroscopy and ultraviolet-visible spectroscopy. The Raman spectra and high-resolution transmission electron microscopy image indicated that a glassy carbon like material was obtained after pyrolysis. The electrical properties of the UCCL could be controlled over a wide range by varying the pyrolysis temperature. Variation in transmittance with conductivity was investigated for applications as transparent conducting films. It was observed that the layers are continuous down to a thickness below 10 nm, with conductivities of 1.6 × 10 4 S/m, matching the best values observed for pyrolyzed carbon films. Further, the chemical stability of the films and their utilization as transparent electrochemical electrodes has been investigated using cyclic voltammetry and electrochemical impedance spectroscopy. © 2010 Elsevier B.V. All rights reserved.

Applied Surface Science

Transparent ultrathin conducting carbon films

This communication describes the electrochemical properties of thin pyrolytic carbon (PyC) films created using a reliable, non-catalytic chemical vapour deposition (CVD) process. After deposition, the electron transfer characteristics of the films are optimised using a simple oxygen plasma treatment. The redox probes Ru(NH3)63+/2+, Fe(CN)63-/4- and Fe3+/2+ are employed to demonstrate that the resulting material is endowed with a large electrochemical surface area and outstanding electron transfer properties. Atomic force microscopy (AFM), Raman and X-ray photoelectron spectroscopy (XPS) are used to elucidate the morphology and chemical composition of the electrode surfaces. This material represents a new class of carbon electrode, and its large densities of edge-plane sites and oxygenated functionalities make it an ideal candidate for electrochemical sensor applications. © 2010 Elsevier B.V. All rights reserved.

Electrochemistry Communications

Thin film pyrolytic carbon electrodes: A new class of carbon electrode for electroanalytical sensing applications

We demonstrate the growth of graphene films on nickel substrates by chemical vapour deposition using acetylene at temperatures as low as 750 °C, opening a viable route for its scalable production. Raman spectroscopy was used to confirm defect-free mono and multilayer graphene at and above this temperature, and of defective graphene at lower temperatures. Atomic force microscopy and scanning electron microscopy performed directly on the films give an indication of graphene flake size, morphology and also the topography on substrate. An unexpected dependence of graphene thickness on precursor dwell time is reported. This together with low temperature growth suggests deficiencies in existing growth models and hints at a more complicated growth mechanism. © The Electrochemical Society.

ECS Transactions

Low temperature graphene growth

In this paper we analytically compute the strength of nonlinear interactions in a triad, and the energy exchanges between wave-number shells in incompressible fluid turbulence. The computation has been done using first-order perturbative field theory. In three dimensions, magnitude of triad interactions is large for nonlocal triads, and small for local triads. However, the shell-to-shell energy transfer rate is found to be local and forward. This result is due to the fact that the nonlocal triads occupy much less Fourier space volume than the local ones. The analytical results on three-dimensional shell-to-shell energy transfer match with their numerical counterparts. In two-dimensional turbulence, the energy transfer rates to the nearby shells are forward, but to the distant shells are backward; the cumulative effect is an inverse cascade of energy. © Indian Academy of Sciences.

Pramana - Journal of Physics

Local shell-to-shell energy transfer via nonlocal interactions in fluid turbulence

In this paper a procedure for large-eddy simulation (LES) has been devised for fluid and magnetohydrodynamic turbulence in Fourier space using the renormalized parameters. The parameters calculated using field theory have been taken from recent papers by Verma [1,2]. We have carried out LES on 64 3 grid. These results match quite well with direct numerical simulations of 1283. We show that proper choice of parameter is necessary in LES.