Semiconductor nanowires have the potential to be important building blocks in this area and are therefore attracting much attention from researchers. The appeal of this technology lies in the ability to fine-tune the wavelength. For example, the nanowire indium gallium arsenide (InGaAs) can be adjusted from the near infrared to the infrared region, making it suitable for applications in infrared emission lasers and photovoltaics.
The main challenge when producing semiconductor nanowires from materials such as InGaAs is controlling the nanowire composition, and achieving homogeneity along and across the nanowires. This is essential if the nanowires are to have any practical or commercial use.
PhD student Ms Amira Ameruddin, under the supervision of Prof. Chennupati Jagadish at the Australian National University (ANU), is studying the chemical composition of InGaAs nanowires. She used energy dispersive X-ray mapping with the scanning transmission electron microscope (STEM) in the AMMRF (now Microscopy Australia) at the Australian National University to observe cross-sections of the nanowires. These techniques revealed that the nanowires have high-quality crystallinity, and uniform morphology and composition when grown under certain controllable conditions.
Her STEM results helped Ms Ameruddin to identify the optimum conditions for producing homogeneous nanowires. This is a significant step towards realising the full potential of InGaAs nanowires in future applications – including solar energy.
STEM images of cross-sections of InGaAs nanowires showing non-uniform (left) and uniform (right) composition.
October 24, 2014
