Associate Professor of Electrical and Computer Engineering
Dr. Stiff-Roberts received both the B.S. degree in physics from Spelman College and the B.E.E. degree in electrical engineering from the Georgia Institute of Technology in 1999. She received an M.S.E. in electrical engineering and a Ph.D. in applied physics in 2001 and 2004, respectively, from the University of Michigan, Ann Arbor, where she investigated high-temperature quantum dot infrared photodetectors. Dr. Stiff-Roberts joined Duke University in August 2004, and she is currently an Associate Professor.
Appointments and Affiliations
- Associate Professor of Electrical and Computer Engineering
- Faculty Network Member of The Energy Initiative
- Office Phone: (919) 660-5560
- Email Address: firstname.lastname@example.org
- Web Page:
- Ph.D. University of Michigan at Ann Arbor, 2004
- M.Sc.Eng. University of Michigan at Ann Arbor, 2001
- B.S.E.E. Georgia Institute of Technology, 1999
- B.S. Spelman College, 1999
Nanomaterials resulting from quantum confinement in three dimensions, known as nanoparticles or quantum dots, exhibit unique characteristics compared to conventional, bulk materials because of their small size, and because nanomaterials can be tailored to exhibit desired properties by controlling their synthesis and their incorporation into thin films. My research group investigates two different types of quantum dots. First, epitaxial quantum dots (EQDs) are inorganic, compound semiconductor nanomaterials synthesized in ultra-high vacuum, crystal growth systems, such as molecular beam epitaxy (MBE). These nanostructures are three-dimensional islands with a lens or pyramid shape that are affixed to a substrate and result from strained-layer epitaxy, which occurs due to the lattice mismatch between the EQD material and a surrounding compound semiconductor material (matrix). Second, colloidal quantum dots (CQDs) are dielectric, semiconductor, or metallic nanomaterials synthesized by inorganic chemistry and surrounded by organic molecules such that they are soluble. These nanostructures often have a spherical shape and are frequently embedded in an organic matrix material, such as charge conducting polymers. These material systems are then called organic/inorganic hybrid nanocomposites. Hybrid nanocomposites are especially interesting because they could enable a new class of optoelectronic devices that are low-cost, can be deployed in novel ways, and can provide multiple functions for unique applications. For example, the simultaneous detection of light across different wavelength regions, or multi-spectral photodetection, could be achieved by integrating different CQDs in a single device. An important challenge to making useful devices from hybrid nanocomposites is controlling the synthesis of thin films. A novel component of my research is a hybrid nanocomposite thin film deposition technique known as matrix-assisted pulsed laser evaporation (MAPLE). My group has established a new approach to MAPLE deposition that drastically expands its applicability to numerous material systems and yields thin films with structural properties comparable to the best achieved using traditional solution-based techniques.An important aspect of my work is to demonstrate the value added by MAPLE in terms of electrical and optical properties of hybrid nanocomposite thin films, as well as enhanced device performance and unique device structures that can be achieved.
- ECE 230L: Introduction to Microelectronic Devices and Circuits
- ECE 340L: Optics and Photonics
- ECE 391: Undergraduate Research in Electrical and Computer Engineering
- ECE 392: Undergraduate Research in Electrical and Computer Engineering
- ECE 496: Special Topics in Electrical and Computer Engineering
- ECE 521: Quantum Mechanics
- PHYSICS 320L: Optics and Photonics
- VMS 325L: Optics and Photonics
Representative Publications: (More Publications)
- A.D. Stiff-Roberts, Quantum dot infrared photodetectors, Comprehensive Semiconductor Science and Technology, vol 6 (2011), pp. 452-485.
- R. Pate, K. R. Lantz, A. Dhawan, T. Vo-Dinh, and A. D. Stiff-Roberts, Resonant Infrared Matrix-Assisted Pulsed Laser Evaporation of Inorganic Nanoparticles and Organic/Inorganic Hybrid Nanocomposites, AIP Conference Proceedings (International Symposium on High Power Laser Ablation), vol 1278 (November, 2010), pp. 812-823 [abs].
- L. Chen, H. Yang, Z. Qiang, H. Pang, L. Sun, Z. Ma, R. Pate, A. Stiff-Roberts, S. Gao, J. Xu, G. J. Brown, and W. Zhou, Colloidal quantum dot absorption enhancement in flexible Fano filters, Applied Physics Letters, vol 96 (February, 2010), pp. 083111 [abs].
- A. D. Stiff-Roberts, K. R. Lantz, and R. Pate, Room-temperature, mid-infrared photodetection in colloidal quantum dot/conjugated polymer hybrid nanocomposites: a new approach to quantum dot infrared photodetectors, Journal of Physics D: Applied Physics, vol 42 (November, 2009), pp. 234004 [abs].
- R. Pate, K. R. Lantz, and A. D. Stiff-Roberts, Resonant infrared matrix-assisted pulsed laser evaporation of CdSe colloidal quantum dot/poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-(1-cyano vinylene)phenylene] hybrid nanocomposite thin films, Thin Solid Films, vol 517 (October, 2009), pp. 6798-6802 [abs].
- Nanomaterials (Quantum Dots)
- Organic/Inorganic Hybrid Nanocomposites
- Matrix-Assisted Pulsed Laser Evaporation
- Molecular Beam Epitaxy
- Photonic/Optoelectronic Devices
- Editorial Board, Scientific Reports, Nature Publishing Group, Quantum Physics
- Technical Committee, IEEE Electron Devices Society (EDS), Optoelectronic Devices
- IEEE Senior Member
- Materials Research Society
- National Society of Black Physicists
- American Physical Society
- American Chemical Society