Zernike Institute for Advanced Materials Colloquium W. Heiss
|05 June 2008||FWN-Building 5111.0080, Nijenborgh 4, 9747 AG, Groningen|
|Speaker:||Prof. Dr. W. Heiss|
|Affiliation:||Johannes Kepler Univ. Linz, Austria|
|Title:||Colloidal nanocrystals for electronic applications|
|Date:||Thu Jun 5, 2008|
|Start:||16.00 (Doors open and coffee available at 15.30)|
Colloidal nanocrystals are attracting significant interest in bio and medical sciences due to their size tunable physical properties and their high flexibility for surface functionalisation. There are, however, also examples for the application of nanocrystalline materials as the active component in opto-electronic devices, which exhibit a superior performance as compared to their counterparts based on classical inorganic heterostructures. Whereas the vast majority of research on colloidal nanocrystals is devoted to materials operating in the visible spectral region, our workgroup focuses on nanocrystals for applications in the infrared. Therefore, we have developed the synthesis of various nanocrystals from narrow-gap materials, such as HgTe, PbSe or SnTe. These materials have been used, e. g., fort he demonstration of photoconductive detectors, simply fabricated by ink-jet printing, exhibiting cut-off wavelength up to 3 m m. Furthermore, we have used the colloidal nanocrystals also to sensitize polymer based photodiodes fort he infrared.
Beside the infrared active nanocrystals our group has also developed metal-ferrite nanocrystals with well controlled sizes and shapes. These nanocrystals have an antiferromagnetic core and a ferrimagnetic shell, which is interacting with the core via exchange interactions at the interfaces. These interactions result in profound changes of the hysteresis loops, exhibiting vertical shifts or exchange bias effects. These nanocrystals are not only of interest for applications in magneto-electronic devices, but they exhibit also an enormous tendency for self assembly into ordered superstructures.
|Last modified:||22 October 2012 2.30 p.m.|