Dr. Ehsan ELAHI<\/span>, IAP Physics Seminar Series will occur on Tuesday 28 May 24, at 15:15 <\/b>at the UM6P campus (Ryad 8, 1st floor<\/strong>).<\/p>\n Abstract:<\/span><\/b><\/span> \u00a0<\/span>Biography<\/span><\/b><\/span>:<\/span>
\n<\/span>Postdoctoral researcher at the Department of Physics (Sejong University, Seoul, South Korea).<\/span><\/p>\n
\n<\/span><\/b><\/span>Since the discovery of graphene, research into other two-dimensional materials has started. After this, a variety of van der Waals (vdW) crystal formations, such as 2D transition metal dichalcogenides (TMDCs) and hexagonal boron nitride (h-BN), have been extensively studied over the past two decades for their various properties. We constructed a heterostructure p-n diode based on MoTe2<\/sub>\u00a0and SnS2<\/sub>. Sweeping the back-gate voltage (Vbg<\/sub>) effectively results in a high rectification ratio of 2.79×105<\/sup>\u00a0and the lowest ideality factor (\u03b7) is 1.25 attained at Vbg<\/sub>= -30V. The interlayer electron-hole recombination is responsible for the variation in rectification behavior. This photodiode has effective photodetection and promising merit statistics as a function of time at the incident light’s wavelengths (\u03bb=220-970 nm). The maximum change in photocurrent (Iph<\/sub>) is 90 nA measured at Vds<\/sub>=0.9 V, and the device exhibited a high responsivity (R) of 5.8×104\u00a0<\/sup>mAW\u22121<\/sup>, while detectivity\u00a0<\/b>is calculated to be about 2.47×1010<\/sup>\u00a0Jones respectively at 220 nm wavelength of incident light illuminated with power 11mW\/cm2<\/sup>. We have evaluated the Hall effect in various devices and attained the maximum magnetoresistance (MR) value of 3.3×103\u00a0<\/sup>% by encapsulating the multilayer flake of WTe2<\/sub>\u00a0with h-BN. We also observed the Nernst effect and saw a remarkable enhancement in Nernst voltage with increasing WTe2<\/sub>\u00a0flake\u2019s thickness. The maximum value of Nernst voltage (Vxy<\/sub>) is 52<\/span>\u00a0\u03bc<\/span>V attained and the Nernst coefficient (Sxy<\/sub>) is 220\u00a0<\/span>\u03bc<\/span>V\/K with a temperature gradient of 0.054 K\/\u00b5m. As a result, we illustrate the function of WTe2<\/sub>\u00a0in its transport characteristics, which can play a vital role in future spintronic and spin-caloritronic-based applications.<\/span><\/p>\n
\n<\/span><\/b>Ehsan ELAHI currently works as a postdoctoral researcher at the Department of Physics (Sejong University, Seoul, South Korea). He obtained his M.Sc. in Electronics from Quaid-i-Azam University Islamabad Pakistan and his M.Phil. from Riphah International University Lahore Campus, Punjab, Pakistan. He attained his doctorate degree from the Department of Physics, Sejong University, Seoul South Korea.\u00a0 Ehsan’s research interests include 2D materials (TMDCs), 2D Ferromagnetic materials, Electronics, Optoelectronics, Spintronics, and Spin-caloritronics. He has published 30 articles in various reputed journals with 370 citations.\u00a0<\/span><\/p>\n