Transparent organic/inorganic nanocomposites for tunable full-color upconversion

Abstract

Transparent medium that gives emission covering the entire color space may find applications in fields such as display and photonics. However, it is technically difficult to access these materials through the combination of emission spectra from different codoped ions in a single host, as energy transfer via inter-ion coupling is unavoidable. Here we demonstrate a simple method for realizing tunable upconversion (UC) emission through a nanocrystal (NC)-polymer nanocomposite. In our process, the wet-chemistry derived NaYF4:RE (RE: rare earth) NCs with pure red, green and blue UC emission were incorporated into a polymer matrix at a concentration that efficiently suppress inter-particle coupling, such that the emissions from each NC are well preserved. The combination of emissions from different types of NCs with selected ratios, therefore, is able to produce emission spectra at any color coordinate in a predictable manner. The emission color of this composite can be further tuned by the pumping intensity of the near infrared laser as well as the density of the NCs in the composite. The method demonstrated here may find applications in both 2D and 3D display technologies and related photonic devices.

Current Advances in Lanthanide‐Doped Upconversion Nanostructures for Detection and Bioapplication

“…In addition to the above applications demonstrated, upconversion nanostructures could also be used for solar energy harvesting, anticounterfeiting, fingerprint detection, 3D‐displays, and so on. Photovoltaics and photocatalysis are very important applications in solar energy harvesting.…”

Na+-Driven Nucleation of NaYF4:Yb,Er Nanocrystals and Effect of Temperature on Their Structural Transformations and Luminescent Properties

“…Upconversion (UC) luminescence generates visible emission via the near-infrared (NIR) excitation process of multiphotons. Upconversion nanoparticles (UCNPs) have attracted extensive attention due to their enormous utility in the fields of bioimaging, cancer therapy, nanothermometry, , solid-state lasers, solar cell spectral conversion, , three-dimensional displays, − and optical memory. , Near-infrared light possesses a long penetration depth in tissues, generates a high signal-to-noise ratio, minimizes irradiation damage, and suppresses autofluorescence. Therefore, UCNPs exhibit advantages over conventional organic phosphors and semiconductor quantum dots .…”

Solar Blind UV Light Induced Photo‐Voltage from Transparent Y2O3: Eu‐PMMA Nanocomposite Film

“…There, Y 2 O 3 as a stable host and Eu 3+ ion is luminescence center . An inorganic‐organic nanocomposite film with high transparency for the solar blind light is fabricated by similar process and it was coated onto a silicon glass substrate, which meanwhile serves as an filter for solar blind light. The down‐conversion luminescence in the visible range from the inorganic‐organic nanocomposite film passes the glass substrate and is then absorbed by Si‐APD detector and produces photo‐voltage.…”