The gist of it: a new blue light s-SNOM technique has just been developed by researchers that lets us dive deep into the nanoscale world of wide-bandgap materials, like those used in blue LEDs.
Researchers at Brown University have succeeded in the coupling of blue light to scattering-type scanning near-field microscopy (s-SNOM). s-SNOM is a technique used to study the properties of materials like semiconductors at the nanoscale level. They hope rto get better insights into semiconductors used in blue LED technology.
In the past, researchers have typically used longer wavelength optical sources (such as near-infrared light) for s-SNOM, which limited the study of wide bandgap materials like silicon (Si) and gallium nitride (GaN). These materials are important for various technological applications. In this recent work, they used femtosecond pulses at 410 nm to generate terahertz pulses directly from bulk silicon, achieving nanoscale resolution. This method allows them to obtain spectroscopic information that was not accessible using near-infrared excitation.
The researchers also developed a theoretical framework to analyze the results of this new method. This framework accounts for the nonlinear interaction between blue light and the material, enabling accurate extraction of material parameters. This development opens up new possibilities for studying wide-bandgap materials on the nanoscale using s-SNOM techniques, which could have significant implications for understanding and developing advanced materials and technologies.
Moreover, the successful coupling of blue light to s-SNOM can be applied to the study of blue LEDs. Blue LEDs are made from wide-bandgap materials, like GaN, which this new s-SNOM technique aims to investigate on the nanoscale. Using blue light s-SNOM, researchers can study the properties of GaN and other materials with nanoscale resolution. By obtaining spectroscopic information and accurately extracting material parameters using the new theoretical framework developed for blue light s-SNOM, researchers may be able to enhance the design and fabrication of blue LED devices and potentially discover new ways to optimize their performance.
Reference
Pizzuto, A., Ma, P. & Mittleman, D.M. Near-field terahertz nonlinear optics with blue light. Light Sci Appl 12, 96 (2023). https://doi.org/10.1038/s41377-023-01137-y
