Academy of Sciences of Moldova

1. Academy of Sciences of Moldova Nanofabrication and characterization of ZnO nanorod arrays and branched nanorods for device applications Oleg LUPAN Technical University of Moldova, MD 2004 Chisinau, MoldovaUniversity of Central Florida, Orlando, FL 32816 lupan@physics.ucf.edu lupan@mail.utm.md Academy of Sciences of Moldova

2. Collaborations with the UCF Teams & Equipment available at the UCF and MCF Synthesis and advising – Dr. Lee Chow MCF - XRD, FIB device fabrication – Dr. G. Chai XPS – Dr. B. Roldan, Dr. A. Naitabdi Micro-Raman – Dr. A. Schulte, S. Park CL spectra – Dr. L. Chernyak, L. Lopatiuk-Tirpak TEM – Dr. Helge Heinrich SEM, EDX – Dr. G. Chai, H. Khallah Academy of Sciences of Moldova

3. Collaborations with the Moldova Teams TechnicalUniversity of Moldova Technical University of Moldova MD. Scintific advising – Prof. Dr.hab. T. Shishiyanu RPP, Hall – Dr. S. Shishiyanu Gas sensitivity – Prof. Dr. V. Sontea Characterizations – Dr. S. Railean Academy of Sciences of Moldova PL – Dr. Hab. V. Ursaki, Institute of Applied Physics, MD Acad. I. Tigineanu, Academy of Sciences of Moldova National Center for Materials Study and Testing EDX, SEM – PhD. E. Monaico, NCMST, TUM, Moldova Academy of Sciences of Moldova

4. Nanofabrication and characterization ofZnO nanorod arrays and branchednano/microrods for device applications 4 Introduction and Motivation • ZnO is a key functional material exhibiting: • near-ultraviolet emission, • transparent conductivity • semiconducting, magnetic, and piezoelectric properties. • It has a: • wide direct band gap (3.37 eV),& • large exciton binding energy (60 meV) • excellent chemical, mechanical, and thermalstability[1, 2] • Zinc oxide has extensive commercial use during the past 100 years [3] in: • optoelectronics • nano/microelectronics • sensors, transducers, • hydrogen storage material and • biomedicine. • ZnO is a phosphor materials with ability to retain a high efficiency, even at low-voltage excitation[1–8]. Academy of Sciences of Moldova

5. Department of PhysicsUniversity of Central Florida Department of MicroelectronicsTechnical University of Moldova Introduction and Motivation 5 • Nanostructures, ->nanorods,->nanowires,->nanotubes,->nanobelts, have attracted extraordinary attention for their potential applications in device and interconnect integration innanoelectronics and molecular electronics. • Control the • particle size& morphology of nanostructures is of crucial importance from a fundamental and industrial point of view Academy of Sciences of Moldova

6. 35 DeviceFabricationsat the MCF, UCF In-situ lift-out fabrication and characterizations of ZnO branched nanorods - based nano/microsensors Academy of Sciences of Moldova

7. 50 Conclusions • The nanorod arrays and branched chemical deposited zinc oxide as gas sensors & solar cells. • The merit of this technology is in • simplicity of the process, • economy in energy, • structures with high efficiency, • short duration, • energy save, • accessible auxiliary materials & • nonsophisticated equipment. Academy of Sciences of Moldova

8. Conclusions By this technique has been fabricated different shaped-nanosensors & preliminary investigated their gas sensitivity to H2, O2, oxygen partial pressure, UV sensitivity, relative humidity, alcohol and ammonia gases. Academy of Sciences of Moldova

9. 52 Future work • We plan further investigations with different dopants and second components in ZnO, etc architectures are underway • othernanoarchitectures&nanostructures • multilayer structures… • Nanorod p-n junctions!!!!! & devices for sensor & high-tech applicationsofnanostructured metal oxide material devices Academy of Sciences of Moldova

10. 53 Acknowledgements • This work described here was made possible in part by an Award No.MTFP-1014 for young researchers of the Moldovan Research and Development Association under the funding from the U.S. Civilian Research and Development Foundation (CRDF) with support from U.S. Department of State Academy of Sciences of Moldova

11. 53 Acknowledgements • Financial support by the Project 321b/s from the Ministry of Education and Science of Moldova, • and Project 032P from Supreme Council for Research and Technological Development of the Academy of Sciences of Moldova are gratefully acknowledged. Academy of Sciences of Moldova

12. 54 Publications - Dr. LUPAN Oleg et.al. Jan-May-2007 • [1] O. Lupan, G. Chai, L. Chow, "Hydrogen nanosensor on single nanorod" US patent pending, May, 2007. • [2] S. Shishiyanu, T. Shsishiyanu, O. Lupan “Gas sensor" MD patent registered #4639 and pending, May, 2007. • [3] O. Lupan,L. Chow, SYNTHESIS AND CHARACTERIZATIONS OF ZnO NANORODS ARRAYS FOR SOLAR CELL AND CHEMICAL SENSOR APPLICATIONS, Proceedings of NSTI Nanotechnology Conference and Trade Show, May 20-24, 2007, Santa Clara, California, U.S.A., ISBN 1420063766 Vol. 4, pp. 457-460. • [4] O.Lupan, L. Chow, S. Shishiyanu, V. Ursaki, E. Monaico, T. Shishiyanu, B. Roldan, A. Naitabdi,A. Schulte, S. Park,Nanostructured zinc oxide synthesized by successive chemical solution deposition for solar cells and gas sensor applications, submitted to Materials Research Bulletin, April 2007. • [5] V. V. Ursaki, O. Lupan, L. Chow, I. M. Tiginyanu, V. Zalamai, Rapid thermal annealing induced change of the mechanism of multiphonon resonant Raman scattering from ZnO nanorods, submitted April, 2007, accepted Solid State Communications. • Other 5 submitted Papers to International peer-review Journals Academy of Sciences of Moldova

13. 2 accepted Poster Papers accepted and Presented by Dr. LUPAN Oleg 20-24 May-2007 • NSTI Nanotechnology Conference and Trade Show, May 20-24, 2007, Santa Clara, California, U.S.A., ISBN 1420063766 Vol. 4, pp. 457-460 Academy of Sciences of Moldova

14. Young generation of engineers and scientists in USA & Moldova • Undergraduate students (4+) • MSc (1+) • Graduate students or PhD students(3+) Questions??? Academy of Sciences of Moldova

15. Q & A, please ? ! Thank You !!! lupan@physics.ucf.edulupanoleg@yahoo.com Academy of Sciences of Moldova