Accession Number : ADA473573


Title :   Development of Highly Ordered Heterostructured Semiconductor Nanowire Arrays for Sub-Wavelength Optical Devices


Descriptive Note : Final rept. Jul 2004-Mar 2007


Corporate Author : TORONTO UNIV (ONTARIO) DEPT OF METALLURGY AND MATERIALS SCIENCE


Personal Author(s) : Ruda, Harry ; Nair, Selvakumar


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a473573.pdf


Report Date : Jun 2007


Pagination or Media Count : 31


Abstract : Methodology for efficient growth of semiconductor nanowires of several Il-VI (ZnSe, ZnO, znS) and III-VI (GaAs, InSb) nanowires was developed and optimized. Based on optical and transport characterization measurements, defect states responsible for quenching of band-edge luminescence were identified and post-growth treatments were devised to eliminate those defects and to achieve strong excitonic emission. Carrier trapping dynamics was elucidated by ultrafast time-resolved optical pump-probe measurements. Optimized ZnSe nanowires were shown to exhibit an exceptionally high photoconductive response of 22A/W in a single nanowire transistor device. Manganese doped ZnO nanowires were fabricated and above room temperature ferromagnetism was achieved. Transport measurements showed these wires to be n-type with a degenerate carrier distribution. The experimental efforts were supplemented by modeling that included design of high Q-factor nanowire array photonic cavities using as well as a theory of excitons in nanowires.


Descriptors :   *PHOTODETECTORS , *PHOTOCONDUCTIVITY , *FERROMAGNETISM , *EXCITONS , METHODOLOGY , OPTIMIZATION , PHOTONIC CRYSTALS , NANOTECHNOLOGY , CHEMICALS , OPTICAL DETECTORS , SEMICONDUCTORS , CATALYSTS


Subject Categories : Optical Detection and Detectors


Distribution Statement : APPROVED FOR PUBLIC RELEASE