Ultrafast and Nanoscale Photonics Group
Arup Neogi, Department of Physics
Sponsors:
• National Science Foundation
• US Department of Energy
• Japan Soc. for Promotion of Sciences
Research Areas
http://www.phys.unt.edu/research/photonic/website/
1. Nanostructured Optoelectronic materials for efficient light emission
2. Biophotonic materials; for hybrid molecular electronics and photonics
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Oligonucleotide based Single Molecule
Nanoscale UV Photodetector (A. Neogi et al)
Objectives:
To develop GaN based novel hybrid
molecular semiconductors for UVvisible photodetectors
Self-assembled
guaninosine
molecule with
strong intrinsic
dipole moment
GaN
I-V characteristics of GaN based single
molecule
guaninosine
photodetector
showing rectification at 100 nm length of
self-assembled organic crystal.
7.03
54 Device
Photocurrent (a.u.)
7.02
7.01
7.00
6.99
6.98
6.97
6.96
280
300
320
340
* MRS Best paper award 2005
360
380
Wavelength (nm)
400
420
440
460
Photocurrent
measurement
shows
a
semiconductor like behavior with a cut-off
wavelength at 327 nm (3.79 eV), larger than
silicon devices, at lower bias. The bandgap also
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changes with bias.
GaN Semiconductor Quantum dots
based light emitters (A. Neogi)
344 nm –347 nm
Near-field emission from a single cluster of GaN/AlN quantum dot for
UV light emission
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