Nanorods with multidimensional optical information beyond the diffraction limit

Shihui Wen,Yung Doug Suh,Gungun Lin,Jiajia Zhou,Yongtao Liu,Dayong Jin,Fan Wang,Bingyang Shi

doi:10.1038/s41467-020-19952-x

Abstract

Precise design and fabrication of heterogeneous nanostructures will enable nanoscale devices to integrate multiple desirable functionalities. But due to the diffraction limit (~200 nm), the optical uniformity and diversity within the heterogeneous functional nanostructures are hardly controlled and characterized. Here, we report a set of heterogeneous nanorods; each optically active section has its unique nonlinear response to donut-shaped illumination, so that one can discern each section with super-resolution. To achieve this, we first realize an approach of highly controlled epitaxial growth and produce a range of heterogeneous structures. Each section along the nanorod structure displays tunable upconversion emissions, in four optical dimensions, including color, lifetime, excitation wavelength, and power dependency. Moreover, we demonstrate a 210 nm single nanorod as an extremely small polychromatic light source for the on-demand generation of RGB photonic emissions. This work benchmarks our ability toward the full control of sub-diffraction-limit optical diversities of single heterogeneous nanoparticles.

Highlights

Precise design and fabrication of heterogeneous nanostructures will enable nanoscale devices to integrate multiple desirable functionalities
We realize the artful control in the single-axis epitaxial growth of uniform lanthanide-doped heterogeneous nanorods with high-dimensional optical signatures
The principle that directs the controlled epitaxial growth is based on the fact that the surfactants—oleic acid molecules (OAH) prefer to be attached to the (001) facet while the oleic acid anions (OA−) bind more firmly onto the (100)/(010) facets of a β-NaYF4 nanocrystal[30]

Summary

Introduction

Precise design and fabrication of heterogeneous nanostructures will enable nanoscale devices to integrate multiple desirable functionalities. Spherical upconversion nanoparticles (UCNPs) have been created with many unique optical properties, including tuneable colors[8], multiplexed lifetimes[9,10], long-distance energy migration[11], amplified stimulated emissions[12,13,14,15,16] and their responses to external fields of temperature[17] and mechanical force[18], which enables many novel applications, including fullcolor displays[8], solar energy harvesting[19], security inks[9], biomolecular sensing[20], force sensing[21], nanothermometry[22,23], fluorescence microscopy[12], optical multiplexing[9,24], deep-tissue optogenetics[25], multimodal bio-imaging[26,27], and light-triggered drug delivery[28,29]. We demonstrate a 210 nm single nanorod as the smallest polychromatic light source for the on-demand generation of RGB photonic emissions

Methods

Results

Conclusion