Research

My primary research is in the electron transport properties of nanoscale materials. The overall goal of my research is to investigate the fundamental electronic properties of nanostructured materials and to demonstrate prototype functional devices like field effect transistors, single electron transistors, and sensors involving nanomaterials. I pioneered and demonstrated a simple and highly reproducible technique for the fabrication of sub-five nanometer spaced electrodes using colloidal gold nanoparticles and used these electrodes for the fabrication of functional devices including individual nanoparticles, conjugated organic molecules and polymers. In addition, I am also interested in nanocrystal arrays, nanowires, and nanotubes.

Previously, at the University of Cambridge, UK, I explored electron transport properties of two, one and zero dimensional systems based on GaAs/AlGaAs heterostructure. In disordered two-dimensional system in a zero magnetic field, I demonstrated a crossover from Mott variable range hopping (VRH) to Efros-Shklovskii VRH when either the temperature or the carrier density is reduced. I discovered a large increase in magneto resistance in disordered two-dimensional electron systems with the application of a strong in-plane magnetic field. I also measured electron transport spectroscopy of InAs self-assembled quantum dots incorporated in a modulation doped GaAs/AlGaAs heterostructure and demonstrated a quantum Hall - insulator transition in such systems.

NanoScale Quantum Transistors My research group is interested in the fabrication of nanoscale electrical and optical devices consisting of low dimensional chemical nanostructures.

Awards, Honors and Societies

• NSF CAREER Award, 2008-2013
• Junior Associate Member, 2001-2006, International Centre for Theoretical Physics, Trieste, Italy
• Scholarship of the Association of Commonwealth Universities, UK, 1994-1997
• Scholarship from the International Center for Theoretical Physics, Trieste, Italy, 1992-1993
• Received Raja Kali Narayan Scholarship (most prestigious award of Dhaka University), 1990
• Member, American Physical Society

Current Funding

• PI: CAREER: Engineering and Parallel fabrication of Single Electron Transistor Devices Using Carbon Nanotubes
  Agency: National Science Foundation
  Award period: 2/01/2008 - 1/31/2013
• PI: Planar gated organic photovoltaic device
  Agency: National Science Foundation
  Award period: 6/1/2008 Ð 5/31/2011
• PI: Collaborative Research: Integration of Biomolecular Self-Assembly and Capacitance Spectroscopy on Pathogen Diagnostics-On-Chip
  Agency: National Science Foundation
  Award period: 9/1/2008 Ð 8/31/2011
• PI: Room-Temperature Synthesis of Semiconductor Nanowires by Templating Collagen Triple Helices and Their Precise Assembly into Electric Circuits by Biomolecular Recognition
  Agency: Department of Energy (subcontracted from Hunter College of CUNY )
  Award period: 10/15/2007 Ð 10/14/2010

Past Funding

• PI: Design and fabrication of a novel high efficiency organic solar cell
  Agency: UCF Inhouse
  Award period: 05/08/2008 to 05/07/2009
• PI: Low temperature Ð high magnetic field cryostat for quantum transport measurements of nanomaterials and composites
  Agency: UCF/Presidential equipment initiative
  Period: 2/1/07 Ð 6/30/07
• CoPI: Acquisition of transmission electron microscope for polymeric and biological studies at nanoscale
  Agency: UCF/Presidential equipment initiative
  Period: 2/1/07 Ð 6/30/07
• PI : Room temperature single electron transistor using carbon nanotube
  Agency: UCF in house research
  Period: 5/8/07 Ð 5/7/08

Teaching

08/2005 - present:

• Fall 09, PHY 5838 - Special Topics: Physics of NanoElectronic Devices
• Spring 09, PHY 2048, Physics for Scientists and Engineers
• Fall 08, PHY 5846C Methods of Experimental Physics
• Spring 08, PHY 2048, Physics for Scientists and Engineers
• Fall 07, PHY 5846C Methods of Experimental Physics
• Spring 07, PHY 2048, Physics for Scientists and Engineers
• Fall 06, PHY 5846C Methods of Experimental Physics
• Spring 06, PHY 5846C Methods of Experimental Physics

Guest Lectures:

• Fall 07: BSC 3424 Nanobiotechnology: Lecture on Nanodevice fabrication
• Summer 07: Guest lecturer, PHY 6939 - Graduate Research Seminar
• Summer 07: Nano - REU lecture on Nanotechology, July 9, 2007
• Summer 06: Guest lecturer, PHY 6939 - Graduate Research Seminar

Selected Publications

• Talgat M. Inerbaev, Artëm E. Masunov, Saiful I. Khondaker, Alexandra Dobrinescu, Andrei-Valentin Plamadă, and Yoshiyuki Kawazoe, Quantum Chemistry of Quantum Dots: Effects of Ligands and Oxidation. J. Phys. Chem. C, 2009 (in press)

• Paul Stokes, Eliot Silbar(*), Yashira M. Zayas(*) and Saiful I. Khondaker, Solution processed large area field effect transistors from dielectrophoreticly aligned arrays of single-walled carbon nanotubes. Appl. Phys. Lett. 94, 113104 (2009) (* denotes undergraduate students).

• Paul Stokes, Liwei Liu, Jianhua Zou, Lei Zhai, Qun Huo and Saiful I. Khondaker, Photoresponse in large area multi-walled carbon nanotube/ polymer nanocomposite films. Appl. Phys. Lett. 94, 042110 (2009)

• Subhajit Biswas, Soumitra Kar, Swadeshmukul Santra, Y. Jompol, M. Arif and Saiful I. Khondaker, Solvothermal Synthesis of High-Aspect Ratio Alloy Semiconductor Nanowires: Cd(1-x)Zn(x)S, a Case Study. J. Phys. Chem C 113, 3617 (2009).

• Jianhua Zou, Saiful I. Khondaker, Lei Zhai and Qun Huo, A General Strategy to Disperse and Functionalize Carbon Nanotubes Using Conjugated Block Copolymers, Advance Functional Materials 19, 479 (2009).

• Paul Stokes and Saiful I. Khondaker, Controlled fabrication of single electron transistors from single-walled carbon nanotubes, Appl. Phys. Lett. 92, 262107 (2008).

• S. H. Yoon, S. Kumar, G. H. Kim, Y. S. Choi, T. W. Kim, and Saiful I Khondaker, Dielectrophoretic assembly of single gold nanoparticle into nanogap electrodes, Journal of Nanoscience and Nanotechnology 8, 3427 (2008)

• J. Zou, L. Liu, H. Chen, S. I. Khondaker, R. D. McCullough, Q. Huo, and L. Zhai, Dispersion of Pristine Carbon Nanotubes Using Conjugated Block Copolymers, Advanced Materials 20, 2055 (2008)

• Paul Stokes and Saiful I. Khondaker, Local-gated single-walled carbon nanotube field effect transistors assembled by AC dielectrophoresis, Nanotechnology 19, 175202 (2008)

• H. Chen, H. Muthuraman, P. Stokes, J. Zou, J. Wang, Q. Huo, S. I. Khondaker, and Lei Zhai, Dispersion of Carbon Nanotubes and Polymer Nanocomposite Fabrication using Trifluoroacetic Acid as a Co-Solvent, Nanotechnology 18, 415606 (2007).

• L. Wang, D. Fine, S. I. Khondaker, T. Jung, and A. Dodabalapur, "Sub-10 nm conjugated polymer transistors for chemical sensors," Sensors and Actuators B 113, 539 (2006).

• A. Bandyopadhyay, A. K. Ray, A. K. Sharma, and S. I. Khondaker, "Transport through neural network of DNA nanocomposites" Nanotechnology 17, 227 (2006)

• S. I. Khondaker, "Fabrication of nanoscale device using individual colloidal gold nanoparticle," IEE proceedings: circuits, devices and systems (special issue in Nanoelectronics) 151, 457 (2004).

• S. I. Khondaker, Z. Yao, L. Cheng, J. C. Henderson, Y. Yao, and J. M. Tour, "Electron transport through single phenylene-ethynylene moleculear junction," Appl. Phys. Lett. 85, 645 (2004).

• G. H. Kim, J. T. Nicholls, D. A. Ritchie, S. I. Khondaker, C.-T. Liang, and T. W. Kim, "Transport properties in samples containing InAs self-assembled dashes and dots," Journal of the Korean Physical Society 42, S454 (2003).

• L. Wang, T. Jung, D. Fine, S. I. Khondaker, Z. Yao, H. V. Seggern, and A. Dodabalapur, "Nanoscale polymer field effect transistors" Proceedings of the 3rd IEEE Conference on nanotechnology, vol. 2, page 577-580 (2003

• G. H. Kim, J. T. Nicholls, C. T. Liang, D. A. Ritchie , and S. I. Khondaker. "Insulator-quantum Hall liquid transitions in a two-dimensional electron gas using self-assembled InAs dots," Physica E 12, 658 (2002).

• S. I. Khondaker and Z. Yao, "Fabrication of nanometer spaced electrodes using gold nanoparticles," Appl. Phys. Lett. 81, 4613 (2002).

• G. H. Kim, J. T. Nicholls, S. I. Khondaker, I. Farrer, and D. A. Ritchie, "Tuning the insulator quantum Hall liquid transitions in a two-dimensional electron gas using self-assembled InAs," Phys. Rev. B 61, 10910 (2000).

• I. S. Shlimak, S. I. Khondaker, D. A. Ritchie, and M. Pepper, "Influence of parallel magnetic fields on a single-layer two-dimensional electron system with a hopping mechanism of conductivity," Phys. Rev. B 61, 7253 (2000).

• S. I. Khondaker, M. Pepper, D. A. Ritchie, and I. S. Shlimak, "Hopping magneto-resistance in a single 2D layer in parallel magnetic fields," Phys. Stat. Sol. B 218, 181 (2000).

• S. I. Khondaker, J. T. Nicholls, W. R. Tribe, D. A. Ritchie, and M. Pepper, "Single electron transport in samples containing InAs self assembled quantum dashes and dots," Physica E 6, 486 (2000).

• S. I. Khondaker, I. S. Shlimak, J. T. Nicholls, D. A. Ritchie, and M. Pepper, "Crossover phenomenon for two-dimensional hopping conductivity and density of states near the Fermi level," Solid State Commun. 109, 751 (1999).

• S. I. Khondaker, I. S. Shlimak, J. T. Nicholls, D. A. Ritchie, and M. Pepper, "Electron-electron interaction assisted hopping and crossover phenomenon in two-dimensional electron system," Proceedings of 24th Int. Conf. on Physics of Semic., Jerusalem, August 2-7, 1998, Editor David Gershoni, World Scientific, Singapore, CD-part, V-D-5. S. I. Khondaker, I. S. Shlimak, J. T. Nicholls, D. A. Ritchie, and M. Pepper, "Two dimensional hopping conductivity in a delta-doped GaAs/AlGaAs heterostructure," Phys. Rev. B 59, 4580 (1999).