1. Structural and electronic characterization
of single-wall nanotube DNA hybrids
Lolita Rotkina, Stacy E. Snyder,
Slava V. Rotkin
Physics Department &
Center for Advanced Materials and Nanotechnology
Lehigh University

2. Tight-binding results
Self-consistent solution for the charge density of semiconductor [7,0] zigzag NT under DNA wrap perturbation

3. Tight-binding results
Self-consistent solution for the charge density of semiconductor [7,0] zigzag NT under DNA wrap perturbation
Polarization interaction:
for [7,0] NT and {6:1 | 4e} wrap the cohesion energy due to the NT pi-e-system polarization de ~ 0.47 eV/b.p.
interaction with the image charge overestimates C.E.
image charge for semiconductor

4. Randomize DNA potential

5. Scaling results: Gaps in S- M-NTs

6. Scaling results: Gaps in S- M-NTs

7. Scaling results: Gaps in S- M-NTs

8. Novel STM-TEM facility
_____________

9. STM-TEM Nanofactory stage
To be installed inside JEOL 2200FS FEG-TEM
STM-TEM Nanofactory stage by Gatan
All images courtesy Gatan (unless author specified)

10. STM-TEM Nanofactory stage
Nanofactory controller
Side entry TEM sample holder is equipped with a full power STM
TEM-STM Stage
Computerized control

11. STM-TEM Nanofactory stage
Inertial slider-driven coarse movement
Piezo-driven fine movement
Interchangeable sample holders

12. STM-TEM Nanofactory stage
< 1 mm – 1 mm
Inertial slider-driven coarse movement
Sample holder
Piezo-driven fine movement
< 0,1 Å – 2,5 mm
< 1 Å – 20 mm

13. In-situ Characterization STM -TEM
Si whiskers

14. Characterization (1)
Novel characterization technique: transport-STM-TEM combined tool
spring ring
contact pads
and mirror pads
sample holder
membrane
bottom view

15. Characterization (1)
Novel characterization technique: transport-STM-TEM combined tool

16. Characterization (1)
Novel characterization technique: transport-STM-TEM combined tool

17. Characterization (1)
Novel characterization technique: transport-STM-TEM combined tool
5 nm
20 nm
20 nm
HR-TEM Cs aberration corrected dedicated TEM/STEM (Kiely)

18. Charge Trapping and Memory Effects
_____________

19. Characterization (2)
Liquid crystal placement for FET/sensor fabrication (Jagota)
Novel femtosecond characterization technique: fast photoelectric response (Biaggio, COT, Lehigh)

20. Characterization (2)
Keithley Semiconductor Characterization Station 4200 with pA preamplifier.
Custom made low-current low-noise photo-electric probe station (Biaggio, Rotkin)

21. Photoresponse of Polymer-NT FET
sample 3
Id/Vd, mA/V
1.14
1.15
1.16
1.17
1.18
-1.5 V
-1.0 V
-0.5 V
1.5 V
1.0 V
Vd = 0.5 V 25 50 75
100
125
150
175
t, sec
Photoconductance Id/Vd vs time of the light pulse.
Amplitude is independent of Vd (and Vg)

22. Photoresponse of Polymer-NT FET
sample 3 1 2 3 4 5
Qg, nC
t, sec
Ig /Vg, nA/V 1 2 3 4 5 6 7
t, sec 50
100
150
200
Total photocurrent pulse = trapped charge

23. Photoresponse of Polymer-NT FET
Id/Vd / (Idmax/Vdmax), a.u.
sample 3
sample 6 1
1.005
1.01
1.015
1.02
1.025
1.03 20 40 60 80
100
120
140
t, sec
Photoresponse is similar for two different polymer substrates.

24. Hysteresis in SWNT-array Transistors
Experiment: Laminated Device, CVD Tubes
decreasing scan rate
Courtesy J.Rogers
Robert-Peillard, Rotkin, 2005

25. Single NT FET insulator Physics of current hysteresis in NT FETs:
Gate voltage controls the charge of the channel
In addition to the charge stored in the gate (gate capacitance), strong electric field generates charges at the interfaces (add.capacitances)
This shifts the threshold voltage (and changes mobility)
The field is self-consistent with the charge
ground Vd
1D channel
insulator Vg