Fabrication of spectroscopic characterization techniques using an optical fiber-based spectrometer

High-sensitive spectroscopy instruments have been developed to measure thermoluminescence emission (TLE), diffuse reflectance, and photoluminescence (PL). The key features of these instruments are low cost, high resolution, and compact size. For TLE measurement, A Kanthal resistive heating strip with a linear heating rate and Ocean Optics spectra suite software were used. Thermally stimulated emission of light was recorded using a USB4000+ES spectrophotometer in the UV-Vis region. In the TLE spectra, intensity vs wavelength was recorded as a function of temperature. In the high instance TLE spectrum of Al₂O₃, Tm³⁺ measured at 458 K shows peaks at 298, 355, 394, 466, 526, 658, 672, 696, and 713 nm. The UV-Vis DRS spectrum of the ZnO powder sample was measured at room temperature in the wavelength range 230-750 nm. The optical bandgap of ZnO was determined using Kubelka-Munk theory and found to be 3.22 eV. In the PL setup, a xenon lamp as the excitation source, direct-attach cuvette holder, visible light filter, IR filter, and adjustable UV bandpass linear variable filter were used. The excitation wavelength was fixed using a filter, and the emission spectra of samples were recorded. In the PL emission spectrum of Al₂O₃, Tb³⁺ shows bands at 382, 420, 438, 462, 487, 543, 586, and 623 nm, which are characteristic of Tb³⁺ ions. The obtained PL results are compared with data acquired using the Hitachi (F-2700) fluorescence spectrometer. This cost-effective spectroscopy instrument will be beneficial in materials science research in order to investigate the optical properties of the materials by study of TLE, PL, and diffuse reflectance.