Photon Avalanching Nanoparticles (ANPs)

As a PhD student at Columbia University, my research project is to characterize the optical properties of photon avalanching nanoparticles. The material, upconverting nanoparticles (UCNPs), is manufactured by our collaborators at the Molecular Foundry at the Lawrence Berkeley National Laboratory. A detailed explanation can be found in a previous blog: An Introduction to Upconverting Nanoparticles.

My goal is to understand these nanoparticles at a single particle level. This involves building an optical system that couples into a microscope and an ultra precise piezo actuated stage. An APD or CCD detector is then connected to image the nanoparticles. In addition to imaging, we also further characterize them with AFM, SEM and XPS.

After 2 years of work, we discovered the avalanching nature of these UCNPs. This is quite a phenomenal property, as it has not previously been realized in a nanostructure previously. We are preparing a patent for this class of materials with the Columbia Technology Ventures. In addition, our paper has been accepted by the journal Nature for application. I will attached a link here once it is published. For now, you may view the preprint here:

In addition, I have also presented this work at the APS March meeting in 2020: Xu, Emma, et al. “Avalanching Upconverting Nanoparticles for Super Resolution Imaging.” Bulletin of the American Physical Society 65 (2020).