Analysis of Optical Absorbance Spectra for the Determination of ZnO Nanoparticle Size Distribution, Solubility, and Surface Energy

Abstract

We present a model to calculate particle size distributions (PSDs) of colloidal ZnO nanoparticles from their absorbance spectra. Using literature values for the optical properties of bulk ZnO and correlating the measurement wavelengths in the UV-visible regime with distinct particle sizes by a tight binding model (TBM), an algorithm deconvolutes the absorbance spectra into contributions from size fractions. We find an excellent agreement between size distributions determined from TEM images and the calculated PSDs. For further validation, bimodal PSDs have been investigated and an approach to determine not only particle size but also solid concentration is introduced. We will show the applicability of our model by the determination of temperature-dependent ripening rates, which enables the calculation of solubilities, surface tensions, and the activation enthalpy of ripening. In principle, our methodology is applicable to different semiconductor nanoparticles in various solvents as long as their bulk properties are known and scattering is negligible.

Analysis of Particle Size Distributions of Quantum Dots: From Theory to Application

“…et al, 2003a;Pesika N.S. et al, 2003b;Segets D. et al, 2009;Segets D. et al, 2012;Viswanatha R. and Sarma D.D., 2006). Despite differences in the exact deconvolution procedure, they all use the same basic assumptions and restrictions, namely i) semiconductor nanoparticles with a direct band gap which are small enough that the scattering contribution to the total extinction is negligible and quantum confinement occurs, ii) a monotone dependency between particle size and dots with a mean diameter of 3.2 nm for different excitation energies.…”

Investigation of the size–property relationship in CuInS2quantum dots

“…PSDs were determined from absorbance spectra according to Segets et al [32][33][34] In its current form, the method is based on a linear superposition of the different particle size fractions, an assumption which has been already reported by various groups [42][43][44][45] …”

“…Prior to classification, a detailed characterization of the feed material was carried out by transmission electron microscopy (TEM), analytical ultracentrifugation (AUC) and optical spectroscopy. Absorbance spectra were converted into PSDs by a previously described deconvolution technique that has been successfully applied to ZnO, 32 PbS(e) 33 and ZnS 34 QDs. The crystal structure and composition of the feed as well as the isolated fractions after classification were investigated by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and inductively-coupled plasma optical emission spectroscopy (ICP-OES).…”

Synthesis and Characterizations of Zinc Oxide Nanoparticles for Antibacterial Applications

“…Zinc oxide NPs has unique physical and chemical properties, such as high chemical stability, high electrochemical coupling coefficient, broad range of radiation absorption and high photostability, is a multifunctional material [1,2]. It has tremendous scientific and technological interest due to direct wide band gap energy (3.37 eV), large exciton-binding energy (60 meV) and high thermal and mechanical stability at room temperature make it attractive for potential use in electronics, optoelectronics and laser technology [3,4].…”