Akademickie Centrum Materiałów i Nanotechnologii AGH zaprasza na seminarium, które odbędzie się w formie hybrydowej 5 maja 2022 r. o godz. 14.00.
Wykład zatytułowany „Luminescence and diffraction imaging of nitride semiconductor thin films and nano/microstructures” wygłosi dr Jochen Bruckbauer (University of Strathclyde, Glasgow, Wielka Brytania).
The scanning electron microscope (SEM) is an extremely versatile platform for non-destructive imaging of the optical, structural, electrical, compositional and defect properties of a wide range of materials. In this presentation the focus lies on the two electron diffraction-based techniques of electron backscatter diffraction (EBSD), electron channelling contrast imaging (ECCI) and cathodoluminescence (CL) hyperspectral imaging in the SEM to obtain complementary information on the structural and optical properties of group III nitride semiconductor thin films and nanostructures. Correlating the luminescence properties to structural information, such as crystal structure, crystal orientation and misorientation, grain boundaries, strain and structural defects, such as threading dislocations and stacking faults, is often crucial to the optimisation of nitride-based (opto)electronics devices. Due to their unique properties, such as a variable band gap from the deep UV to the near infrared, the group III nitride material system has a large range of applications from solid-state lighting, high power electronics, medical devices, water purification, sterilisation, wireless communication and agriculture. I will present correlated and complementary measurements to investigate material challenges from a range of nitride thin films and nano/-microstructures: (i) investigation of defects in thin films with semi-polar orientations to overcome detrimental polarisation effects of the commonly used polar growth orientation; (ii) the impact on luminescence of the crystal polarity of nanostructures; (iii) the imaging and characterisation of threading dislocation, the predominant extended defect in polar nitrides. Finally advances in direct electron detector technology for EBSD will be discussed.
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