Experimental studies of some opto-electronic properties of thin films of galena

An experimental investigation into some of the optical and electronic properties of electron beam evaporated thin films of natural galena is presented in this study. In particular, we focus our attention on potentialities of thin films of natural galena for making thin film resistors. The dark (i)I-V characteristics and (ii) sheet resistance and electrical conductivity as a function of temperature, as also (iii) sheet-resistance and I-V characteristics as a function of irradiance constitute the study of the electronic properties while (i) refractive index, (ii) optical density and (iii) transmittance account for the optical properties. The temperature dependent electrical conductivity for these films is shown to obey our studies reported earlier for natural galena crystals. The very large resistivity of these films is accounted for by a very large inter-grain distance as is indicated by the scanning electron micrographs. The energy gap-refractive index values are in complete accord with the Moss relation.