Optical band gap, extinction coefficient and refractive index of K(NO3)(1-x)(ClO3)(x) films

作者：Nkum R K^*; Abavare E K K; Ampong K; Boakye F

来源：Optoelectronics and Advanced Materials-Rapid Communications, 2012, 6(11-12): 1170-1173.

• Films
• Optical properties
• Solid solution
• K(NO3)(1-x)(ClO3)(x)

The optical band gap, extinction coefficient and refractive index of K(NO3)(1-x)(ClO3)(x) films have been investigated from absorbance and transmittance measurements. The absorption in K(NO3)(1-x)(ClO3)(x) solid solutions is found to be due to an allowed direct transmission from the top of the valence band to the bottom of the conduction band at the centre of the Brillouin zone. The band gap of the K(NO3)(1-x)(ClO3)(x) solid solutions studied in this work decreases with increasing chlorate concentration. Thus as the concentration of the chlorate ions increases, the absorption edge is shifted to lower energies. The extinction coefficient is lowest for the pure potassium nitrate sample. The introduction of chlorate ions results in an increase in the extinction coefficient and hence the conductivity of the films. It is also observed that the refractive index of the films at photon energy = E-g increases with increasing chlorate ion concentration. With higher chlorate content the band gap shrinks and the refractive index shifts towards longer wavelength.

• 出版日期2012-12