A5022411909- Ferroelectric and Piezoelectric Materials
- Semiconductor materials and devices
- Ga2O3 and related materials
- GaN-based semiconductor devices and materials
- Electronic and Structural Properties of Oxides
- ZnO doping and properties
- Acoustic Wave Resonator Technologies
- Multiferroics and related materials
- Photonic and Optical Devices
- Metal and Thin Film Mechanics
- Dielectric materials and actuators
- Advanced Photocatalysis Techniques
- Semiconductor Lasers and Optical Devices
- Silicon Carbide Semiconductor Technologies
- Silicon Nanostructures and Photoluminescence
- Transition Metal Oxide Nanomaterials
- Radio Frequency Integrated Circuit Design
- Underwater Acoustics Research
- Thin-Film Transistor Technologies
- Advanced Sensor and Energy Harvesting Materials
- Advanced Memory and Neural Computing
Indian Institute of Science Bangalore
2014-2024
We demonstrate epitaxial β-Ga2O3/GaN-based vertical metal–heterojunction-metal (MHM) broadband UV-A/UV-C photodetectors with high responsivity (3.7 A/W) at 256 and 365 nm, UV-to-visible rejection >103, a photo-to-dark current ratio of ∼100. A small (large) conduction (valence) band offset the heterojunction pulsed laser deposition (PLD)-grown β-Ga2O3 on metal organic chemical vapor (MOCVD)-grown GaN-on-silicon registry, as confirmed by X-ray diffraction (XRD) azimuthal scanning, is exploited...
Lead-free, silicon compatible materials showing large electromechanical responses comparable to, or better than conventional relaxor ferroelectrics, are desirable for various nanoelectromechanical devices and applications. Defect-engineered electrostriction has recently been gaining popularity to obtain enhanced at sub 100 Hz frequencies. Here, we report record values of electrostrictive strain coefficients (M
Integrating Ga2O3 power electronics on a silicon substrate can reduce the system cost and improve heat dissipation, but high on-resistance in vertical devices is its major drawback. We solve this challenge with an electrically conductive epitaxial TiN (100) buffer layer that be deposited Si without SiOx formation. While our thin MgO interlayer strategy prevents GaTiOx at TiN-Ga2O3, it also results large resistance. By tailoring Ga2O3:Si "seed layer" deposition process, we achieve...
Heterogenous integration of complex epitaxial oxides onto Si and other target substrates is recently gaining traction. One the popular methods involves growing a water-soluble highly reactive sacrificial buffer layer, such as Sr3Al2O6 (SAO), at interface functional oxide on top this. To improve versatility layer transfer techniques, it desired to utilize stable (less reactive) layers without compromising rates. In this study, we utilized combination chemical vapor deposited (CVD) graphene 2D...
In this report, we demonstrate direct epitaxial integration of β-Ga2O3 on a (400) oriented silicon insulator substrate toward deep-UV (DUV) optoelectronics. The 550 nm thick epitaxial-β-Ga2O3 films are deposited onto Si(100) using two-step buffer and epilayer scheme. orientation relation between β-Ga2O3, MgO, silicon(100) is given by (400)β-Ga2O3||(100)MgO||(100)Si ⟨010⟩β-Ga2O3||⟨011⟩MgO||⟨110⟩Si. presence rotational variants confirmed X-ray diffraction transmission electron microscopy....
We report on the demonstration and investigation of Ta2O5 as high-\k{appa} dielectric for InAlN/GaN-MOS HEMT-on-Si. thickness 24 nm constant ~ 30 was sputter deposited InAlN/GaN HEMT investigated different post deposition anneal conditions (PDA). The gate leakage 16nA/mm at -15 V which 5 orders magnitude lower compared to reference HEMT. 2-dimensional electron gas (2DEG) density found vary with annealing temperature suggesting presence net charge Ta2O5/InAlN interface. Dispersion in...
The integration of BaTiO3 with Si(100) is essential to exploit its ferroelectric capabilities in the well-established Si-complementary metal–oxide–semiconductor (CMOS) technological platform. To enable this goal, epitaxial films both in-plane and out-of-plane polarization are demonstrated on just a single TiN layer that also CMOS-compatible. This change direction brought about very simply by changing growth temperature. Piezo force microscopy optical second-harmonic generation measurements...
We report a novel Sc/Al/Ni/Au metal scheme for Ohmic contacts to InAlN/GaN HEMT structures on silicon. A contact resistance of 0.39 Ω-mm with low surface roughness 20± 3 nm the annealed has been achieved using this scheme. The microstructure region under revealed formation ~60 deep ScGaN inclusions in GaN channel layer. thin (~3-5 nm) non-uniform layer ScInAlN is observed top InAlN barrier. Field-emission found be dominant conduction mechanism. Polarization mismatch arising due structural...
We present a comprehensive insight into ferroelectric material development and characterisation required for next-generation electro-optic modulators. show that simple electric of polarisation is insufficient. Even characteristics are subject to the nature material.
Abstract Lead-free, silicon compatible materials showing large electromechanical responses comparable to, or better than conventional relaxor ferroelectrics, are desirable for various nanoelectromechanical devices and applications. Defect-engineered electrostriction has recently been gaining popularity to obtain enhanced at sub 100 Hz frequencies. Here, we report record values of electrostrictive strain coefficients (M 31 ) frequencies as 5 kHz (1.04×10 − 14 m 2 /V 1 kHz, 3.87×10 15 kHz)...
Abstract Semiconducting oxides are often stable, non-toxic, and can potentially be deposited at a low cost. The existence of with appropriate bandgap (<1.8 eV) reasonable mobility points towards the alluring possibility employing as absorbers in ‘all-oxide’ solar cells. However, oxide have remained elusive due to debilitating effects mobility, deep-defects, inefficient doping, which degrade their optoelectronic performance. In this work, we report annealing on properties an emerging...
A submicron gate normally off AlGaN/GaN high‐electron‐mobility transistor (HEMT) with a high on‐current and threshold voltage ( V TH ) is demonstrated. The high‐performance device realized utilizing recess length depth of 200 124 nm, respectively. recess‐etched region has roughness 0.7 nm. Various recess‐etch depths dielectric annealing conditions are used to tune . optimized exhibits an 500 mA mm −1 5 V, measured breakdown characteristics the devices their limitations investigated using...
Lead free, silicon compatible materials showing large electromechanical responses comparable to, or better than conventional relaxor ferroelectrics, are desirable for various nanoelectromechanical devices and applications. Defect-engineered electrostriction has recently been gaining popularity to obtain enhanced at sub 100 Hz frequencies. Here, we report record values of electrostrictive strain coefficients (M31) frequencies as 5 kHz (1.04 x 10-14 m2 per V2 1 kHz, 3.87 10-15 kHz) using...
Heterogenous integration of complex epitaxial oxides onto Si and other target substrates is recently gaining traction. One the popular methods involves growing a water-soluble highly reactive sacrificial buffer layer, such as Sr3Al2O6 (SAO) at interface, functional oxide on top this. To improve versatility layer transfer techniques, it desired to utilize stable (less reactive) layers, without compromising rates. In this study, we utilized combination chemical vapor deposited (CVD) graphene...
We report a novel tetramethylammonium hydroxide (TMAH) pretreatment to minimize the contact resistance <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\left(R_{C}\right)$ </tex-math></inline-formula> using Ti-based Ohmic contacts InAIN/GaN-on-Si RF HEMTs. The TMAH treatment is shown etch dislocation sites on surface, which act as medium for Ti diffusion into GaN during annealing. This enhances TiN...
We report on the demonstration of a deep sub-micron normally-off AlGaN/GaN HEMT with high on-current and threshold voltage (VTH). The high-performance device was realized by utilizing gate recess length depth 200 nm 124 respectively. etched region had roughness 0.7 nm. Various etch depths dielectric annealing conditions were used to tune VTH. optimized exhibited VTH 500 mA/mm 5 V measured breakdown characteristics devices their limitations investigated using 2D-TCAD simulation. penetration...