Nanoparticle Devices. S. A. Campbell, ECE C. B. Carter, CEMS H. Jacobs, ECE J. Kakalios, Phys. U. Kortshagen, ME. Institute of Technology

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1 Nanoparticle Devices S. A. Campbell, ECE C. B. Carter, CEMS H. Jacobs, ECE J. Kakalios, Phys. U. Kortshagen, ME

2 Applications of nanoparticles Flash Memory Tiwari et al., Appl. Phys. Lett. 68, 1377, Vertical Transistors Nishigushi and Oda, J. Appl. Phys. 88, 4186, Silicon LEDs Park et al., Appl. Phys. Lett., 78, 2575, Quantum Phosphor Rowher et al., Sandia Natl. Lab., Silicon Laser Canham, Nature 408, 411, 2000.

3 The Vision: Nanoparticle Transistors Vertical Schottky Barrier FET Does not require doping Can be built on any kind of substrate 3D integration Scales easily to very small size What is needed? Gate oxide Source Gate Drain Schottky Barrier FET Single crystal, defect-free silicon nanoparticles

4 Improved Solar Cells Light-induced defect creation (Staebler-Wronski effect) limits efficiency of solar cells. New materials appear promising: nanostructured silicon

5 Systems Devices Jacobs Campbell microscale Characteriztion nanoscale Characterization Kakalios Carter Synthesis Kortshagen

6 Uwe Kortshagen Silicon nanoparticles for electronic devices Dept. of Mechanical Eng. Novel electronic devices such as vertical transistors Solid-state lighting: silicon quantum dots as environmentally benign material More efficient solar cells with increased stability ~ 2-nm silicon crystallite in amorphous silicon matrix

7 Uwe Kortshagen Nonthermal plasmas for silicon nanocrystals Design plasma properties for optimal particle properties silicon particles for electronic devices nanoparticles with ~1 trap site / particle nonagglomerated silicon nanocrystals with narrow size distribution.

8 C. Barry Carter Nanoparticles of Silicon Dept. of Ch. E. & Materials Science Structure by high-resolution TEM Ceramics, semiconductors and metals Link to properties through collaborations The new HRTEM Shape of nanoparticles Defects and surface reactions TEM: the essential tool for nanoparticle research

9 C. Barry Carter Devices and True Nanoparticles Link to Devices Morphology and Perfection Crystals in Amorphous Films Phase transformations Crystal of Si in amorphous Si Students: Chris Perrey & Julia Deneen Stacking fault in a 2nm particle! Twin boundary in a 1.5nm particle! The new HRTEM

10 Jim Kakalios Opto-Electronic Properties of Nanostructured Silicon Thin Films School of Physics and Astronomy Thin Film PECVD Amorphous Silicon (a-si:h) Preferred for TFT s and Solar Cells Light-Induced Defect Creation Major Liability Silicon Nanocrystals Embedded Within Amorphous Silicon (a/nc-si:h) Resist Light- Induced Degradation

11 Jim Kakalios TEM confirms nanocrystals in a/nc-si:h films Optical and Electrical Properties of Nanostructured Material Comparable to Best Quality a-si:h Light-Induced Decay of Photosensitivity (Ratio of Photo-to-Dark Conductivity) Reduced in a/nc-si:h Films

12 Steve Campbell Nanoparticle Devices Electrical and Computer Engineering Limits to the scaling of planar CMOS in sight Possible new directions: 3D integrated circuits Mixing electronics/optics /magnetics/etc. on the same chip Single crystal nanoparticles can be used for both purposes

13 Steve Campbell Methods for making single crystal semiconductor nanoparticles Building and characterizing nanoparticle devices MSM structures Silicon transistors Metal Metal Silicon Nanoparticle Source Gate Drain Schottky Barrier FET NP properties highly dependent on surface Good interfaces possible Outstanding performance expected due to low C Gate oxide

14 Heiko O. Jacobs Self-Assembly of Nanoparticle Building Blocks Electrical and Computer Engineering Dept. Electrostatic interaction can be used to position 5 nm - 50 μm sized components Sub-100 nm resolution has been accomplished Programmability will be possible using programmable electrodes/receptors RIGID SUPPORT charged area

15 Heiko O. Jacobs Parallel charge patterning by Electric Nanocontact Lithography Electrostatically driven self-assembly of nanoparticles from the liquid and gas phases SWNT Rope bundle Developed a technique to pattern charge with 100 nm resolution Developed a nanoxerographic printer to print nanoparticles with ~60 nm resolution