SIUC Physics Seminar
School of Physics and Applied Physics, Southern Illinois University--Carbondale
2025 September 19 Friday 3:00 PM:
Physics Seminar in Neckers 440
Title: High Temperature Photoconductivity of 2D Layers of MoS\(_2\)
Speaker: Dushmantha Gusthignghadurage
Affiliation: Southern Illinois University--Carbondale
Abstract:
MoS\(_2\) is in Transition Metal dichalcogenides (TMDCs) category which is
a widely researched material due to its electronic behavior
such as photoconductivity. In this dissertation we mainly focus on
high temperature Photoresponse behavior of Metal-Semconductor-Metal (MSM)
MoS\(_2\) photodetectors. Photodetectors are one of the main part of
electronic based applications such as telecommunications
and opto-electronic industry. Here we designed MSM photodetectors
using prepatterned gold electrodes and few layers of MoS\(_2\) flakes
which were synthesized using mechanical exfoliation assisted
dry transfer method. Then to understand the photoconductive behavior,
devices were used for opto-electronic measurements. So here we present
the electronic and optoelectronic properties of 2D layers of MoS\(_2\)
flakes within the temperature (\(T\)) range of (290 K < \(T\) < 360 K).
Temperature-dependent photoconductivity measurements performed within
this range, using a continuous laser source of \(\lambda = 640\,\text{nm}\)
over a range of effective illuminating laser intensities,
\(P_\text{eff} \;(0.1\,\mu\text{W} < P_\text{eff} < 0.8\,\mu\text{W})\)
indicates the possibility of achieving high photoresponsivity beyond
room temperatures and at ambient conditions. For example, it is found
that the achieved peak Responsivity (\(R\)) and Detectivity (\(D\))
are \(8.88\,\text{A/W}\) and \(6.1 \times 10^{10}\,\)Jones at
\(0.5\,\text{V}\) respectively. Furthermore, the impact of temperature
and incident light power on gamma factor (\(\gamma\))
at high temperature range is thoroughly examined. Apart from that
effect of the Annealing on photoconductivity was observed and reported.
Biography:
Dushmantha Gusthigngnhadurage is a Ph.D. student in Applied Physics at
Southern Illinois University Carbondale. He holds two Master's degrees in physics,
one from Southern Illinois University Carbondale and another from
the University of Strasbourg, France,
and a Bachelor's degree from the University of Kelaniya, Sri Lanka.
His research focuses on the High Temperature-dependent photoconductivity
of 2D materials under the guidance of Prof. Saikat Talapatra.
In addition to his research, he serves as a Teaching Assistant in
the Department of Physics and as a Graduate Assistant at
the Micro Imaging and Analysis Center, where he operates
the Scanning Electron Microscope (SEM) for clients.
Last updated on
by K V Shajesh
(kvshajesh@gmail.com).