Faculty Img
  • Phone:

    +966-13-849-9398

  • Email:

    adas@pmu.edu.sa

  • Office No:

    F-016

  • Aparna Das, Ph.D.

  • Job Title :

    Assistant Professor

  • College :

    College of Sciences and Human Studies


  • Department :

    Mathematics & Natural Sciences


I am a physicist with extensive international research and teaching experience. My research focus is study of semiconductor materials at nanoscale: synthesis and characterization (optical, electrical, microscopic, and structural characterizations) of low dimensional semiconductor heterostructures (Quantum wells, Quantum dots and Nanowires) and apply them to high performing electronic and optoelectronic devices. Specifically, my research interest is focused on development of functional materials for applications in sensors, optoelectronics, power devices and energy generation & storage. I hold a master of science degree (MS) in photonics and doctoral degree (Ph.D.) in physics (major)/nanophysics/material physics.

My experience includes nanostructure growth using bottom up methods (mainly using molecular beam epitaxy(MBE), chemical vapor deposition (CVD)), top down methods including E-beam lithography, characterization using high resolution transmission electron microscopy (HRTEM), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), UV and IR photoluminescence, transmission spectroscopy, time-resolved photoluminescence, Raman Spectroscopy and electrical characterizations including Hall Effect measurements. I have extensive clean room experience with photolithography, electron-beam lithography, wire bonding, profilometer, wafer saw, spin coating, plasma-enhanced chemical vapor deposition (PECVD), sputtering, reactive-ion etching (RIE), electron beam evaporator and rapid thermal processing (RTP).

My postdoctoral experiences include working as a scientist at the University of California, Los Angeles (UCLA), USA (California NanoSystems institute, Electric Engineering Department and as an Experienced researcher: Nanowiring-Marie Curie Initial Training Network at Georg-August-Universität Göttingen, Germany.

The focus of my PhD thesis work at Commissariat à l'énergie atomique (CEA), France, was the study of semiconductor quantum dots for opto-chemical sensor application. My dissertation work comprised the epitaxial growth of (In)GaN QDs superlattices both in polar (0001) and semipolar (11-22) crystallographic orientations by molecular beam epitaxy, for application as optical transducers for chemical. This work was developed within the EU project “Dotsense” (FP7-ICT-STREP). My graduate research includes masters research and as a project associate at Centre of Excellence in Lasers and Optoelectronic Sciences/ International School of Photonics, CUSAT, India, research assistant at SNDL, Sungkyunkwan University, Korea.  


  • Ph.D.  in Physics/Nanophysics,  CEA (Alternative Energies and Atomic Energy Commission) /University of Grenoble, France.
  • Masters in Photonice, CUSAT, India


Journal Publications

2017
[1] Optical properties of bimodally distributed InAs quantum dots grown on digital AlAs 0.56 Sb0.44 matrix for use in intermediate band solar cells

Mukul C. Debnatha), Baolai Liang, Ramesh B. Laghumavarapu, Guodong Wang, Aparna Das, Bor-Chau Juang, and Diana L. Huffaker
Journal of Applied Physics (submitted)
2016
[2] Comparative study of photoluminescence from In0.3Ga0.7As/GaAs surface and buried quantum dots

Wang, Guodong; Liang, Baolai; Juang, Bor-Chau; Das, Aparna; Debnath, Mukul; Huffaker, Diana; Mazur, Yuriy; Ware, Morgan; Salamo, Gregory
Nanotechnology 27, 465701 (2016)
2014
[3] High Precision, Electrochemical Detection of Reversible Binding of Recombinant Proteins on Wide Bandgap GaN Electrodes Functionalized with Biomembrane Models

Nataliya Frenkel, Jens Wallys, Sara Lippert, Jörg Teubert, Stefan Kaufmann, Aparna Das, Eva Monroy, Martin Eickhoff, and Motomu Tanaka
Advanced Functional Materials 24, 4927-4934 (2014)
2013
[4] III-N nanostructures for optical gas detection and pH sensing in liquids

S. Paul, K. Maier, A. Das, F. Furtmayer, A. Helwig, J. Teubert, E. Monroy, G. Müller, and M. Eickhoff
P roc. SPIE 8725, 87250K (2013)
[5] InGaN/GaN quantum dots as optical probes for the electric field at the GaN/electrolyte interface

J. Teubert, S. Koslowski, S. Lippert, M. Schafer, J. Wallys, G. Dimitrakopulos, Th. Kehagias, Ph. Komninou, A. Das, E. Monroy, and M. Eickhoff
J. Appl. Phys. 114, 074313 (2013)
2012
[6] Morphology and origin of V-pits in semipolar (11-22) InGaN

A. Lotsari, A. Das, Th. Kehagias, Y. Kotsar, E. Monroy, Th. Karakostas, P. Gladkov, Ph. Komninou, G.P. Dimitrakopulos
J. Cryst. Growth 339, pp. 1-7 (2012)
[7] Structural properties of semipolar InGaN/GaN quantum dot superlattices grown by plasma-assisted MBE

A. Lotsari, G.P. Dimitrakopulos, Th. Kehagias, A. Das, E. Monroy, Ph. Komninou
Microelectronic Engineering 90, pp. 108-111 (2012)
[8] Structure and Strain State of Polar and Semipolar InGaN Quantum Dots

T. Koukoula, A. Lotsari, Th. Kehagias, G. P. Dimitrakopulos, I. Häusler, A. Das, E. Monroy, Th. Karakostas, and Ph. Komninou
Appl. Surf. Sci. 260, pp 7-12(2012)
2011
[9] Improved luminescence and thermal stability of semipolar (11-22) InGaN quantum dots

A. Das, G. P. Dimitrakopulos, Y. Kotsar, A. Lotsari, Th. Kehagias, Ph. Komninou, and E. Monroy
Appl. Phys. Lett. 98, 201911 (2011)
[10] Growth and characterization of polar (0001) and semipolar (11-22) InGaN/GaN quantum dots

A. Das, P. Sinha, Y. Kotsar, P. K. Kandaswamy, G. P. Dimitrakopulos, Th. Kehagias, Ph. Komninou, G. Nataf, P. De Mierry, and E. Monroy
J. Crystal Growth 323, 161 (2011)
[11] Internal Quantum Efficiency of III-nitride Quantum Dot Superlattices Grown by Plasma-Assisted Molecular-Beam Epitaxy

Ž. Gačević, A. Das, J. Teubert, Y. Kotsar, P. K. Kandaswamy, Th. Kehagias, T. Koukoula, Ph. Komninou, and E. Monroy
J. Appl. Phys. 109, 103501 (2011)
[12] Strain relaxation in GaN/AlxGa1-xN superlattices grown by plasma-assisted molecular-beam epitaxy

Y. Kotsar, B. Doisneau, E. Bellet-Amalric, A. Das, E. Sarigiannidou, and E. Monroy
J. Appl. Phys. 110, 033501 (2011)
[13] Strain relaxation in GaN/Al0.1Ga0.9N superlattices for mid-infrared intersubband absorption

Y. Kotsar, P. K. Kandaswamy, A. Das, E. Sarigiannidou, and E. Monroy
J. Crystal Growth 323, 64 (2011)
2010
[14] Indium kinetics during the plasma-assisted molecular-beam epitaxy of semipolar (11-22) InGaN layers

A. Das, S. Magalhaes, Y. Kotsar, P. K. Kandaswamy, B. Gayral, K. Lorenz, E. J. C. Alves, P. Ruterana, and E. Monroy
Appl. Phys. Lett. 96, 181907 (2010)
[15] P-type doping of semipolar GaN(1122) by plasma-assisted molecular-beam epitaxy

A. Das, L. Lahourcade, J. Pernot, S. Valdueza-Felip, P. Ruterana, A. Laufer, M. Eickhoff, and E. Monroy
Phys. Stat. Sol. (c) 7, pp. 1913-1915 (2010)
[16] Performance Improvement of AlN–GaN-Based Intersubband Detectors by Using Quantum Dots

D. Hofstetter, J. Di Francesco, P. K. Kandaswamy, A. Das, S. Valdueza-Felip, and E. Monroy
IEEE Photon. Technol. Lett. 15, pp. 1087-1089 (2010)
[17] Effect of doping on the mid-infrared intersubband absorption in GaN/AlGaN superlattices grown on Si(111) templates

P. K. Kandaswamy, H. Machhadani, Y. Kotsar, S. Sakr, A. Das, M. Tchernycheva, L. Rapenne, E. Sarigiannidou, F. H. Julien, and E. Monroy
Appl. Phys. Lett. 96, 141903 (2010)

[18] Performance improvement of AlN/GaN-based intersubband detectors thanks to quantum dot active regions.

D. Hofstetter, J. Di Francesco, E. Baumann, F. R. Giorgetta, P. K. Kandaswamy, A. Das, S. Valdueza-Felip, and E. Monroy
Proc. SPIE 7808, 78080A (2010)
[19] Polar and Semipolar III-Nitrides for long wavelength intersubband devices.
E. Monroy, P. K. Kandaswamy, H. Machhadani, A. Wirthmüller, S. Sakr, L. Lahourcade, A. Das, M. Tchernycheva, P. Ruterana, and F. H. Julien
Proc. SPIE 7608, 76081G (2010)

[19] Aparna Das, Bimal k. Banik,"Relationship between Antibacterial Activity and Dipole Moment of Organic Drugs"

Invited Presentations

[1] Polar and Semipolar III-Nitrides for long wavelength intersubband devices

 

E. Monroy, P. K. Kandaswamy, H. Machhadani, A. Wirthmüller, S. Sakr, L. Lahourcade, A. Das, M. Tchernycheva, and F. H. Julien
Photonics West (SPIE), San Francisco, U.S.A. January 2010
[2] III-nitride nanostructures for intersubband optoelectronics

E. Monroy, Y. Kotsar, P. Sinha, A. Das, L. Lahourcade, P. K. Kandaswamy, H. Machhadani, S. Sakr, M. Tchernycheva, and F. H. Julien
3rd Int. Symposium on the Growth of III-Nitrides (ISGN3). Montpellier, France. July 2010
[3] III-Nitride semiconductors for intersubband devices

E. Monroy, Y. Kotsar, P. K . Kandaswamy, A. Das, A. Wirthmüller, H. Machhadani, S. Sakr, M. Tchernycheva, F. H. Julien, A. Vardi, and G. Bahir,
Photonics West (SPIE), San Francisco, U.S.A. January 2011
[4] Internal Quantum Efficiency of polar and semipolar InGaN QDs

A. Das, A. Lotsari, Y. Kotsar, G. P. Dimitrakopulos, Th. Kehagias, Ph. Komninou, and E. Monroy
Tata Institute of Fundamental Research (TIFR), India, September 2011
[5] Strain relaxation in GaN/AlGaN superlattices grown by PAMEB for intersubband applications

B. Doisneau, Y. Kotsar, E. Sarigiannidou, E. Bellet-Amalric, A. Das, and E. Monroy
Extended Defects in Semiconductors EDS2012. Thessaloniki, Greece. Sept. 2012
[6] GaN quantum devices for infrared optoelectronics

Monroy, Y. Kotsar, A. Das, S. Valdueza-Felip, E. Bellet-Amalric, C. Bougerol, R. Songmuang, L. Rapenne, E. Sarigiannidou, S. Sakr, M. Tchernycheva, F. H. Julien, E. Gross, A. Pesach, and G. Bahir
4th Int. Symposium on the Growth of III-Nitrides (ISGN4), St. Petersburg, Russia. July 2012

Contributions to international conferences

[1] (Oral) Study of Indium incorporation during the MBE growth of polar and semipolar InGaN layers

A. Das, Y. Kotsar, P. K. Kandaswamy, B. Gayral, and E. Monroy
E-MRS Spring Meeting, Strasbourg, France. May 2010
[2] (Oral) Effect of doping on the mid-infrared intersubband absorption in III-nitride

 

superlattices grown on Si(111) templates

P. K. Kandaswamy, Y. Kotsar, H. Machhadani, S. Sakr, A. Das, M. Tchernycheva, F. H. Julien, and E. Monroy
E-MRS Spring Meeting, Strasbourg, France. May 2010
[3] (Poster) Different In incorporation in polar and semipolar InGaN layers during MBE growth

A. Das, S. Magalhães, Y. Kotsar, P. K. Kandaswamy, B. Gayral, K. Lorenz, E. Alves, and E. Monroy
3rd Int. Symposium on the Growth of III-Nitrides (ISGN3). Montpellier, France. July 2010
[4] (Oral) Effect of doping on the interband and intersubband properties of III-nitride superlattices grown on Si(111) templates

Y. Kotsar, P. K. Kandaswamy, H. Machhadani, S. Sakr, A. Das, M. Tchernycheva, F. H. Julien, and E. Monroy
3rd Int. Symposium on the Growth of III-Nitrides (ISGN3). Montpellier, France. July 2010
[5] (Oral) Study of strain relaxation in GaN/AlGaN superlattices for mid-infrared intersubband absorption

Y. Kotsar, P. K. Kandaswamy, A. Das, L. Rapenne, E. Sarigiannidou, and E. Monroy
16th Int’l Conference on Molecular Beam Epitaxy (MBE2010). Berlin, Germany. August 2010
[6] (Oral) Growth and characterization of polar (0001) and semipolar (11-22) InGaN/GaN quantum dots

A. Das, P. Sinha, Y. Kotsar, P. K. Kandaswamy, S. Magalhães, K. Lorenz, E. Alves, and E. Monroy
16th Int’l Conference on Molecular Beam Epitaxy (MBE2010). Berlin, Germany. August 2010
[7] (Poster) InGaN quantum dot superlattices grown by plasma assisted MBE

T. Koukoula, Th. Kehagias, A. Lotsari, A. Das, E. Monroy, G. P. Dimitrakopulos, and Ph. Komninou
Extended Defects in Semiconductors. Brighton, UK. September 2010
[8] (Oral) Plasma-assisted MBE growth of semipolar (11-22) InGaN layers and GaN/InGaN quantum dots

A. Das, A. Lotsari, S. Magalhães, P. Sinha, G. P. Dimitrakopulos, Th. Kehagias, Ph. Komninou, K. Lorenz, E. Alves, and E. Monroy
International Workshop on Nitride Semiconductors (IWN-2010), Tampa, USA. September 2010
[9] (Oral) GaInN quantum dots as optochemical transducers

J. Teubert, S.Koslowski, A. Das, E. Monroy, and M. Eickhoff
19th European Workshop on Heterostructure Technology (HETECH’10), Crete, Greece. Nov. 2010
[10] (Poster) Structural properties of Semipolar III-Nitride Quantum Dots

G. P. Dimitrakopulos, E. Kalesaki, A. Lotsari, Th. Kehagias, J. Kioseoglou, A. Das, L. Lahourcade, E. Monroy, I. Hausler, H. Kirmse, W. Neumann, Ph. Komninou and Th. Karakostas
19th European Workshop on Heterostructure Technology (HETECH’10), Crete, Greece. Nov. 2010
[11] (Poster) Nanoscale Structure of InGaN Quantum Dot Superlattices Grown by MBE

T. Koukoula, Th. Kehagias, A. Lotsari, A. Das, E. Monroy, G.P. Dimitrakopulos, and Ph. Komninou
19th European Workshop on Heterostructure Technology (HETECH’10), Crete, Greece. Nov. 2010
[12] (Poster) Structure of asymmetric V-defects in semipolar InGaN grown by MBE

A. Lotsari, G. P. Dimitrakopulos, Th. Kehagias, A. Das, E. Monroy, and Ph. Komninou
4th International Conference on Micro-Nanoelectronics, Nanotechnology and MEMS, NCSR-
Democritos, Athens, Greece. Dec. 2010
[13] (Poster) Polar and Semipolar InGaN Quantum Dots

A. Lotsari, T. Koukoula, Th. Kehagias, A. Das, E. Monroy, G. P. Dimitrakopulos, and Ph. Komninou
4th International Conference on Micro-Nanoelectronics, Nanotechnology and MEMS, NCSR-Democritos, Athens, Greece. Dec. 2010
[14] (Poster) Plasma-assisted MBE growth of semipolar quantum dots

A. Das, L. Lahourcade, P. Sinha, G. P. Dimitrakopulos, Th. Kehagias, Ph. Komninou, and E. Monroy
Photonics West (SPIE), San Francisco, U.S.A. January 2011
[15] (Oral) Improved luminescence and thermal stability of MBE-grown semipolar (11-22) InGaN quantum dots

A. Das, Y. Kotsar, A. Lotsari, Th. Kehagias, Ph. Komninou, and E. Monroy
16th European Molecular Beam Epitaxy, Alpe d’Huez, France. March 2011
[16] (Oral) GaN/AlGaN superlattices grown by PAMBE for intersubband applications in the infrared spectral range

Y. Kotsar, A. Das, E. Bellet-Amalric, E. Sarigiannidou, H. Machhadani, S. Sakr, M. Tchernycheva, F. H. Julien, and E. Monroy
16th European Molecular Beam Epitaxy, Alpe d’Huez, France. March 2011
[17] (Oral) Plasma-assisted MBE of GaN/AlGaN multiple-quantum-well structures for intersubband optoelectronics

Y. Kotsar, S. Sakr, E. Sarigiannidou, H. Machhadani, E. Bellet-Amalric, M. Tchernycheva, A. Das, F. H. Julien, and E. Monroy
E-MRS Spring Meeting, Nice, France. May 2011
[18] (Oral) Internal Quantum Efficiency of InGaN quantum dots: Polar vs. Semipolar

A. Das, A. Lotsari, Y. Kotsar, G. P. Dimitrakopulos, Th. Kehagias, Ph. Komninou, and E. Monroy
E-MRS Spring Meeting, Nice, France. May 2011
[19] (Poster) Plasma-assisted MBE of GaN/AlGaN multiple-quantum-well structures for intersubband optoelectronics

Y. Kotsar, S. Sakr, E. Bellet-Amalric, H. Machhadani, B. Doisneau, E. Sarigiannidou, M. Tchernycheva, A. Das, F. H. Julien, and E. Monroy
9th International Conference on Nitride Semiconductors (ICNS9), Glasgow, UK. July 2011
[20] (Poster) InGaN quantum dots as optochemical transducers

J. Teubert, S. Koslowski, A. Das, E. Monroy, and M. Eickhoff
9th International Conference on Nitride Semiconductors (ICNS9), Glasgow, UK. July 2011
[21] (Oral) Nanostructure and Strain State of InGaN Quantum Dot Superlattices Grown by MBE

T. Koukoula, Th. Kehagias, G. P. Dimitrakopulos, A. Lotsari, A. Das, I. Häusler, W. Neumann, E. Monroy, and Ph. Komninou
9th International Conference on Nitride Semiconductors (ICNS9), Glasgow, UK. July 2011
[22] (Poster) Strain and structure of semipolar (11-22) InGaN quantum dots

A. Lotsari, G. P. Dimitrakopulos, Th. Kehagias, T. Koukoula, A. Das, E. Monroy, and Ph. Komninou
9th International Conference on Nitride Semiconductors (ICNS9), Glasgow, UK. July 2011
[23] (Poster) Plasma-assisted MBE of semipolar (11-22)-oriented III-nitrides: 2D layers and nanostructures

A. Das, Y. Kotsar, L. Lahourcade, G.P.Dimitrakopulos, Th. Kehagias, A. Lotsari, T. Koukoula, Ph. Komninou, and E. Monroy
9th International Conference on Nitride Semiconductors (ICNS9), Glasgow, UK. July 2011
[24] (Poster) A structural analysis of semipolar (11-22)-GaN layers grown on m-sapphire by MOVPE and MBE

B. Lacroix, M. P. Chauvat, P. Ruterana, G. Nataf, P. de Mierry, A. Das, and E. Monroy
9th International Conference on Nitride Semiconductors (ICNS9), Glasgow, UK. July 2011
[25] (Oral) Self-Assembled Quantum Dot Superlattices in Semipolar (11-22) III-Nitrides: Stoichiometry, Strain State and Morphology

G. P. Dimitrakopulos, A. Lotsari, E. Kalesaki, J. Kioseoglou, Th. Kehagias, L. Lahourcade, A. Das, E. Monroy, I. Häusler, H. Kirmse, W. Neumann, G. Jurczak , T. D. Young, P. Duewski, Th. Karakostas and Ph. Komninou
E-MRS 2011 Fall Meeting, Warsaw, Poland. Sept. 2011
[26] (Poster) Asymmetric V-defects in semipolar InGaN

A. Lotsari, G. P. Dimitrakopulos, Th. Kehagias, A. Das, E. Monroy, and Ph. Komninou
E-MRS 2011 Fall Meeting, Warsaw, Poland. Sept. 2011
[27] (Poster) Nanostructure and Strain State of InGaN Quantum Dot Superlattices Grown by MBE

T. Koukoula, Th. Kehagias, G. P. Dimitrakopulos, A. Lotsari, A. Das, I. Häusler, W. Neumann, E. Monroy, and Ph. Komninou
E-MRS 2011 Fall Meeting, Warsaw, Poland. Sept. 2011
[28] (Oral) Opto-chemical sensor system based on InGaN/GaN quantum dots for pH detection

S. Paul, A. Helwig, A. Das, J. Teubert, E. Monroy, G. Müller, and M. Eickhoff
Int. Meeting on Chemical Sensors, Nuremberg, Germany. May 2012
[29] (Poster) III-N nanostructures for optical pH-detection

S. Koslowski, S. Lippert, J. Wallys, F. Furtmayr, J. Teubert, A. Das, E. Monroy, G. Dimitrakopulos, P. Komninou, S. Paul, A. Helwig, G. Müller, and M. Eickhoff
Int. Meeting on Chemical Sensors, Nuremberg, Germany. May 2012
[30] (Poster) Anisotropic strain and optical properties of semi-polar (11-22) GaN epilayers grown on m-plane sapphire

N. Hatui, A. Das, E. Monroy, A. Bhattacharya.
International Conference on the Physics of Semiconductors, Zurich, Switzerland. July 2012
[31] (Oral) Direct Imaging of Single GaN Quantum Dots using Helium Temperature Scanning Transmission Electron Microscopy Cathodoluminescence

M. Müller, G. Schmidt, F. Bertram, P. Veit, A. Das, E. Monroy, and J. Christen
9th Intl.Symp. on Semiconductor Light Emitting Diodes (ISSLED 2012), Berlin, Germany. Jul 2012
[32] (Oral) Highly spatially resolved Cathodoluminescence of Single GaN Quantum Dots directly performed in Scanning Transmission Electron Microscope

G. Schmidt, M. Müller, F. Bertram, P. Veit, S. Petzold, A. Das, E. Monroy
Microscopy & Microanalysis 2012 Meeting, Phoenix, US. Aug. 2012
[33] (Oral) Evaluating anisotropic structural properties of semi-polar III-Nitride epilayers using high-resolution x-ray diffraction

N. Hatui, M. Gokhale, A. Das, E. Monroy, and A. Bhattacharya

The 11th Biennial Conference on High Resolution X-Ray Diffraction and Imaging. Saint-Petersburg, Russia. Sept. 2012


Study of semiconductor materials at nanoscale: Synthesis and characterization (optical, electrical, microscopic, and structural characterizations) of low dimensional semiconductor heterostructures (Quantum wells, Quantum dots and Nanowires). Optoelectronic devices, power devices, solar cell and Sensors


Marie Curie Alumni Association