II-VI Semiconductor Quantum Dots: The Evolution of Color Purity with Structure

Abstract

II-VI semiconductor quantum dots such as binary CdTe, CdSe, CdS, ZnO and ternary CdS1-xSex, CdxZn1-xS embedded in glass or deposited on glass substrates as thin film or colloids in aqueous solution structures have potential for technological applications such as light emitting diodes (LED), gas, pressure and temperature sensing detectors and two- or three-dimensional imaging, and solar cells. In this chapter we present a comprehensive study on nanometer-sized crystals fabricated by various routes to exploit the defect structure, progression of stoichiometry, growth kinetics, strain due to lattice mismatch and quantum size effect by employing optical (transmission, photoluminescence and Raman spectroscopy) and structural (SEM and XRD) characterization techniques. We finally scrutinize the evolution of color or emission wavelength with crystallite size dependent band gap energy through colorimetry.