Mn-Doped Multinary CIZS and AIZS Nanocrystals

Abstract

Multinary nanocrystals (CuInS2, CIS, and AgInS2, AIS) are widely known for their strong defect state emission. On alloying with Zn (CIZS and AIZS), stable and intense emission tunable in visible and NIR windows has already been achieved. In these nanocrystals, the photogenerated hole efficiently moves to the defect-induced state and recombines with the electron in the conduction band. As a result, the defect state emission is predominantly observed without any band edge excitonic emission. Herein, we report the doping of the transition-metal ion Mn in these nanocrystals, which in certain compositions of the host nanocrystals quenches this strong defect state emission and predominantly shows the spin-flip Mn emission. Though several Mn-doped semiconductor nanocrystals are reported in the literature, these nanocrystals are of its first kind that can be excited in the visible window, do not contain the toxic element Cd, and provide efficient emission. Hence, when Mn emission is required, these multinary nanocrystals can be the ideal versatile materials for widespread technological applications.

Bicolor Mn-doped CuInS2/ZnS core/shell nanocrystals for white light-emitting diode with high color rendering index

“…5, exhibits six clear hyperfine splittings, and the g factor is 2.008 as well as the hyperfine constants (A) is 68.4G. In the experiment of Pradhan et al, 13 the hyperfine constant of CIZS:Mn NCs is 68G, but the six clear hyperfine splittings cannot be found in the EPR spectra because of the effect from Cu. The clear hyperfine splitting in Fig.…”

“…13 In our experiment, in order to achieve CIS-based NCs with bichromatic emission, we synthesized Mn-doped CIS/ZnS NCs, in which Mn 2þ ions and the CIS core were separated with a ZnS layer so both Mn 2þ ions and CIS cores could emit simultaneously. The obtained Mn-doped CIS-based NCs showed a broad spectral range with two emission peaks at 528 nm and 590 nm, respectively.…”

Large-scale synthesis of single-source, thermally stable, and dual-emissive Mn-doped Zn–Cu–In–S nanocrystals for bright white light-emitting diodes

“…Whereas, the Mn emission instead of band edge emission from the Zn−Cu−In−S was observed in Mn-doped ZnCuInS3 NC system [77]. These non-cadmium doped multinary systems only showed one narrow emission band after introducing Mn ions into host NCs, which would not serve as effective color converter in fabricating WLED with effective white light.…”

Fabrication of MnFe2O4–CuInS2/ZnS magnetofluorescent nanocomposites and their characterization

“…One-pot synthesis requires a balance among all precursors so that magnetic atom doping in the QD lattice can occur, or to facilitate epitaxial growth of the magnetic lattice on the QD lattice. It is challenging to find the right precursors for Cu, In, and Fe (or Ni, Mn) with the balanced reactivities to produce MFNCs with desired properties [17, 28–30]. Moreover, involving magnetic atoms such as Mn in CuInS 2 core or ZnS shell may significantly change the optical properties by re-constructing the semiconductor energy band [30].…”