Research

Research Interests

-Laser micro– and nano-structuring of materials and laser modification of surfaces .

-Semiconductor and optical materials and devices – processing, fabrication and characterization.

-Vacuum microelectronics

-Glassy materials and their applications; chalcogenide glasses.

-Materials characterization by: optical, vibrational, and electron spectroscopy methods; optical, electron and scanning-probe microscopy methods; other optical, electrical, and chemical methods.

-Nanomaterials and nanofabrication.

-Photovoltaics

-Materials and devices for biomedical applications

Current Projects

1. Direct Laser Fabrication of Nano-Sharp Structures on Semiconductor and Metal Thin Films for Microelectronic and Vacuum Microelectronic Applications.

This project is related to a new technique for direct laser fabrication of sharp tips (nanotips) . The method is based on single-pulse UV-laser irradiation of thin films of single-crystal Si on insulator substrates. Possible applications of such structures include: - Vacuum microelectronics: field-emission-based devices such as field emission displays, novel high-current electron beam sources, miniaturized analogs of the vacuum electronics systems from the past. - Scanning probe microscopy techniques: atomic force microscopy (AFM) and related; - Micro-/nano-structuring of surfaces for applications in sensors/MEMS and other. MEMS-based advance memory devices, such as those being developed at Nanochip, Inc.

Possible research directions include:

- Further studies on the formation of the nanotips;

- Characterization of the fabricated structures by various means;

- Formation of tips in vacuum and controlled gas atmosphere;

- Theoretical modeling of the formation mechanism;

- Coating of the tips with other, lower-work-function materials;

- Formation of tips, cones, and bumps on thin films of metals and other semiconductors.

Some references:

- I. Avrutsky, D.G. Georgiev, D. Frankstein, G. Newaz, G. Auner, “Super-resolution in Laser Annealing and Ablation”, Appl.Phys.Lett., 84 (2004) 2391

- D.G. Georgiev , R.J. Baird, I. Avrutsky, G. Auner , G. Newaz, “Controllable Excimer-Laser Fabrication of Conical Nano-Tips on Silicon Thin Films”, Appl.Phys.Lett., 84 (2004) 4881

- D.G. Georgiev, R.J. Baird, I. Avrutsky, G. Auner, G. Newaz, N. Tokranova, “A Systematic Study of the Formation of Nano-Tips on Silicon Thin Films by Excimer Laser Irradiation”, in Micro- and Nanosystems—Materials and Devices, edited by Cengiz S. Ozkan, David A. LaVan, Mark McNie, and Somuri Prasad (Mater. Res. Soc. Symp. Proc. 872, Warrendale, PA , 2005), J13.6

- S. Thanawala, D.G. Georgiev, G. Auner, “Excimer-Laser Fabrication of Micro-Bumps on Platinum Thin Films” , Appl.Phys.Lett., 91 (2007) art.#041912

- J.P. Moening, D.G. Georgiev, “Laser Fabrication of Sharp Conical Microstructures on Si Thin Films by Nd:YAG Laser Single Pulse Irradiation” in Amorphous and Polycrystalline Thin-Film Silicon Science and Technology, edited by A. Flewitt, J. Hou, S. Miyazaki, A. Nathan, and J. Yang, Mater. Res. Soc. Symp. Proc. Vol. 1066, Warrendale, PA, 2008, 1066-A17-04

2. Intermediate Phases in Chalcogenide Glasses and Other Glassy Materials. Optimization of the Glass Structure for Applications in Optoelectronics and Microelectronics

Possible research directions include:

- Optimization of bulk and thin-film glassy materials properties for optoelectronics and microelectronics applications based on the “intermediate phase” concept;

- Rare-earth ion (and other ions for light emission and amplification) host materials;

- Chalcogenide glasses as non-linear optical materials;

- Amorphous « crystalline phase-change memories: Ovonic memories and related

Some references:

- D.G. Georgiev, P. Boolchand, M. Micoulaut, "Rigidity Transitions and Molecular Structure of AsxSe1-x glasses", Phys. Rev. B, 62(2000), R9228

- D.G. Georgiev, M. Mitkova, P. Boolchand, G. Brunklaus, H. Eckert, M. Micoulaut, "Molecular Structure, Glass Transition Temperature Variation, Agglomeration Theory, and Network Connectivity of Binary P-Se Glasses" Phys. Rev. B, 64 (2001), 134204

- Y. Wang, J. Wells, D.G. Georgiev, P. Boolchand, K. Jackson, M. Micoulaut, "Sharp Rigid to Floppy Transition Induced by Dangling Ends in a Network Glass", Phys. Rev. Lett, 87(2001), 185503

- P. Boolchand, D.G. Georgiev, B. Goodman, "Discovery of the Intermediate Phase in Chalcogenide Glasses", J. Optoelectronics and Advanced Materials, 3 (2001), 703

- D.G. Georgiev, P. Boolchand, H. Eckert, M. Micoulaut, K. Jackson " The Self-Organized Phase of Bulk PxSe1-x Glasses", Europhys. Lett., 62 (2003) , 49

- S. Chakravarty, D.G. Georgiev, P.Boolchand, M. Micoulaut, “Aging, Fragility and Reversibility Windows in Bulk Alloy Glasses”, J. Physics-Condensed Matter, 17 (2005) L1

- P. Chen, C. Holbrook, P. Boolchand, D.G. Georgiev, K.A. Jackson, M. Micoulaut, “Intermediate Phase, Network Demixing, Boson and Floppy Modes, and Compositional Trends in Glass transition Temperatures of Binary AsxS1-x System”, Phys. Rev. B 78 (2008) #224208