Optical and thermal properties of glasses and glass-ceramics derived from agricultural wastes

Abstract Agricultural waste ashes are used to synthesize glasses and glass-ceramics by melt-quench technique. The as-prepared as well as heat-treated samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), dilatometer, UV/Visible and photoluminescence spectroscopy. It is observed that, the higher content (> 50 wt%) of rice husk ash (RHA) prevents the formation of the glasses. The optical band gap of as-quenched samples is in wide-band gap semiconductor range , i-e. 3.49–4.17 eV. The coefficient of thermal expansion (CTE) is in the range of 13–16 × 10 −6 /°C measured. All samples are luminescent and show the blue shift as RHA increases in initial composition. The developed materials could find applications in the field of power-generation and UV–Visible light-emitting diode (LED's).