Hue‐ and Chromaticity‐Based Exploration of Surface Complexation‐Induced Tunable Emission from Non‐Luminescent Quantum Dots

Abstract

Herein we report the use of ah ue parameter of HSV (Hue, Saturation and Value) color space-in combination with chromaticity color coordinates-for exploring the complexation-induced luminescence color changes, ranging from blue to green to yellow to white, from a non-luminescent Fe-doped ZnS quantum dot (QD). Importantly,t he surface complexation reactionh elped ap resynthesized non-luminescent Fe-doped ZnS QD to glow with different luminescence colors (such as blue, cyan, green, greenish-yellow,y ellow) by virtue of the formation of various luminescenti norganic complexes (using different external organic ligands), while the simultaneous blue-and yellow-emitting complexf ormation on the surfaceo fn onluminescent Fe-doped ZnS QD led to the generation of white light emission, with ah ue mean value of 85 and a chromaticity of (0.28,0.33). Furthermore, the surface complexation-assisted incorporation of luminescence properties to an on-luminescent QD not only overcomest heir restricted luminescence-based applicationss uch as lightemitting, biological and sensing applications but also bring newer avenues towards unravelling the surface chemistry between QDs and inorganic complexes and the advantage of havinga ni norganic complex with QD for their aforementioned useful applications.Ascertaining the perfect color of al uminescent nanoscale material (such as quantum dot;Q D) plays an important role to define their unique optical characteristics and anticipated luminescenceb ased usagesi nl ight emitting devices (LEDs), bioimaging and optical sensing. [1] Incidentally,t he different color spaces, such as xy chromaticity (CIE xyY), linear-light tristimulus (CIE XYZ, RGB), perceptually uniform (CIE L*u*v*; CIE L*a*b*, nonlinearR 'G'B')a nd hue oriented (Hue, Saturation and Value; HSV), have demonstrated their use in describing the emission properties andn umerous color-based applicationso fQ Ds. [1] Amongt he mentioned four color spaces, HSV is commonly used as ac ylindrical colour-spaceindigitalimaging.I mportantly,t he numerical representation of the spectral color (circular part of the cylinder),d egree to which as ingle channel dominates (radius of the cylinder) andb rightness (height of the cylinder) are identified by their hue (H), saturation( S) and value (V) coordinates, correspondingly. [1] The equations for calculating H, S, and VofH SV color space are given below: [1] HInterestingly, the hue parameter of HSV color space is essential to define their use as an analytical tool for the detection of mechanical strain in polymers, ion sensing, identification of edible oils, pH sensing,n anopalsmonics and naked-eye DNA detection. [1] For example, Hakonen et al. showed the use of hue parameter for the sensing of pH and also demonstrated their superiority compared to ratiometrica nd single wavelength-intensity based pH sensing. [1c] Furthermore, Hakonen et al. also demonstrated the investigation of edible oils-based on the collection and comparing their mean hue values. [1d] Thus, the high precision ability and ...