• About us
• Research
  1. HPCVD
  2. SSMS
  3. NANOCOMPOSITES
• People
  1. N. Dietz
  2. M. Alevli
  3. G. Durkaya
  4. R. Atalay
  5. Former Members
• Contacts

Research Tasks and Results: 


• Design and construction of high-pressure CDV system with integrated real-time optical diagnostics
  Reactor Design - Real-time diagnostic capabilities (2.1 MB)
  
  
• Characterization of reactor gas flow dynamics
  Characterization of reactor flow dynamics (620 KB)
  Flow kinetics at elevated pressures using pulsed precursor injection (400 KB)
  
  
• Real-time optical characterization of the precursors: Identification - flow characterization - Pulsed precursor injection
  Real-time optical characterization of ammonia (NH₃) by UV absorption spectroscopy (1.8 MB)
  Trimethylindium (TMI) charaterization via UV absorption spectroscopy (900 KB)
  
  
  
• Real-time optical analaysis of InN nucleation and thin film formation
  
    Real-time optical characterization of InN chemistry and growth during high pressure vapor phase deposition conditions (1.4 MB)
  
  
  "Indium-nitride growth by HPCVD: Real-time and ex-situ characterization," N. Dietz, book chapter in "GaN-based Materials: Epitaxy and Characterization", ed. Z.C. Feng, Imperial College Press (ICP) pp. 1-31 (2005). preprint PDF file ( 2.4 MB )
  
  
  
  
• InN thin film analysis
  
  Characterization of InN layers grown under HPCVD conditions (1.3 MB - updated May 16, 2005 )
  
  
  "Nucleation and growth of InN by high-pressure chemical vapor deposition: optical monitoring", Poster presentation; PCSI-32 Jan. (2005) (1 MB)
  
  
  "Nucleation and growth of InN by high-pressure chemical vapor deposition: optical monitoring",
  V. Woods, J. Senawirante, and N. Dietz, J. Vac. Sci. Technol. . B 23(4), in print (2005). [ preprint PDF file (550 KB) ]
  
  
  
  
• Theoretical predictions of nucleation and growth kinetics
  Advanced Computational Modeling of Vapor Deposition in a High-Pressure Reactor (600 KB)
  

Collaborators:


• Prof. Klaus J. Bachmann, North Carolina State University     Email: k_bachmann@ncsu.edu


• Prof. Beatriz Cardelino, Spelman College                  Email: cardelino@spelman.edu



This research effort has been supported by NASA Grant# NAG8-1686 and the NASA Collaborative Agreement NCC8-95. Additional support in the reactor design and construction was provided by DOD MURI Grant F-49-620-95-1-0447.

Solid State Molecular Sensor


The objective in this research effort is the design, development and applications of a new and unique integrated Solid-State Molecular Sensor (SSMS) system. The SSMS systems are based on confined, birefringent, heterostructure technology. SSMS systems identify target CB molecules in real-time under ambient conditions. SSMS structures have the ability to detect and discriminate between numerous and varied molecular species. It does so by employing resonant phase- and/or amplitude sensitive detection over a large, tunable spectral range. The SSMS can be made sensitive to one specific group of molecules by setting up appropriated phase matching conditions. The SSMS response is unlike that of a linear waveguide sensor in two primary areas: change of frequency output, and intensity of the output light generated. Both signals are generated in a nonlinear second harmonic generation (SHG) process. This process is very sensitive to small changes in the phase matching conditions. The SSMS is a miniaturized technology. It is easily interfaced with existing Si and III-V compound electronic components. Applications include: quick and remote screening of air pollutants; recognition of CB hazards in the environment, monitoring of surface corrosion/etching processes; as well as bio-medical testing.

The materials development is directed towards the growth and optimization of nearly lattice-matched II-IV-V₂ chalcopyrite (CP) compound semiconductors on IV, III-V and II-VI substrates, with focus on the materials systems:

1.         Zn(Ge_1-xSi_x)P₂,
2.         Zn(Ge_1-xSi_x)N₂,   and
   
3.         Zn(Ge_1-xSi_x)As₂,
   

Research Tasks: 


• Theory & simulation of nonlinear optical (NLO) interactions in confined birefringent heterostructures
  
• Fabrication of confined, birefringent II-IV-V² heterostructures by OMCVD: materials development and optimization
  
• Structural and optical characterization of layers, interfaces and surfaces
  
• In-situ and ex-situ materials defect characterzation
  
• Characterization of nonlinear/linear optical properties in birefringent layers and optically/electrically confined multiple heterostructures
  
• Theoretical predictions, validation and nonlinear optical device design
  

Industrial Interaction


• Xoetronics LLC
  
  

Collaborators (Theory):


• Prof. Stockman, Department of Physics & Astronomy, Georgia State University (GSU)
  
• Prof. Madarasz, Center for Applied Optics, University of Alabama in Huntsville (UAH)
  
  

Collaborators (Experiment):


• Prof. Bachmann, Department of Materials Science, North Carolina State University (NCSU)
  
• Prof. Hoffmann, Department of Physics, Technical University Berlin (TUB)