May 10, 2014
Synchrotron: high spatial and temporal resolution of nitride-wire light emission
Contact : Joël Eymery

Nonpolar InGaN/GaN multiple quantum wells grown on the sidewalls of c-axis GaN wires.
ESRF X-ray synchrotron focused beams are now available to study the light emission of
these wires with high spatial and temporal resolutions

Synchrotron nanobeams opens new opportunities to investigate nanostructures with high spatial (sub-100 nm) and temporal (sub-50 ps) resolutions. Thanks to the parallel exploitation of multiple analytical tools (fluorescence, diffraction and  photoluminescence), it is demonstrated how hard X-ray nanoprobes can be currently used in nanowire research. Direct correlations of composition, structural and optical properties are obtained, providing new insights into the underlying growth mechanisms and device behaviour.

A collaboration between teams of INAC, ESRF and Institute of Microelectronics of Madrid has demonstrated the interest of this techniques, amongst others, for the study of InGaN/GaN core-shell quantum wells grown around GaN wires already used in light electroluminescent diodes. The hard X-ray excitation generates a blue light, which can be correlated to the indium-content in the quantum wells and to the position on the facets (center or edges). The time-resolved measurement of the decay time of the blue emission (around 0.1 ns) generated by the X-ray flash confirms the efficiency of the radiative mechanism associated to these quantum wells that exhibit no piezoelectric fields due to their crystallographic orientation.

More details in Advanced Materials doi: 10.1002/adma.201304345
 

 

Last update : 06/30 2014 (1042)

 

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