RESUMO
Hybrid perovskites are emerging as a promising, high-performance luminescent material; however, the technological challenges associated with generating high-resolution, free-form perovskite structures remain unresolved, limiting innovation in optoelectronic devices. Here, we report nanoscale three-dimensional (3D) printing of colored perovskite pixels with programmed dimensions, placements, and emission characteristics. Notably, a meniscus comprising femtoliters of ink is used to guide a highly confined, out-of-plane crystallization process, which generates 3D red, green, and blue (RGB) perovskite nanopixels with ultrahigh integration density. We show that the 3D form of these nanopixels enhances their emission brightness without sacrificing their lateral resolution, thereby enabling the fabrication of high-resolution displays with improved brightness. Furthermore, 3D pixels can store and encode additional information into their vertical heights, providing multilevel security against counterfeiting. The proof-of-concept experiments demonstrate the potential of 3D printing to become a platform for the manufacture of smart, high-performance photonic devices without design restrictions.
RESUMO
Although trapping and manipulation of small objects have been of interest for a range of applications and many clever techniques have been devised, new methods are still in great demand for handling different materials and geometries. Here, we report on an electrostatic trap that is created in an aqueous medium between the aperture of a nanopipette and a glass substrate without the need for external potentials. After a thorough characterization of the trapping conditions, we show that we can displace or release a particle at will. Furthermore, we demonstrate trapping and manipulation of nanoparticles and lipid vesicles attached to lipid bilayers, paving the way for controlled studies of forces and diffusion associated with biological membranes. We expect the technique to find interesting applications also in other areas such as optonanofluidics and plasmonics.