Preparation and Optical Properties of Evaporated β‐HgS Films

A modified vacuum deposition technique has been developed for producing thin films of HgS with cubic structure. Transmission and reflection measurements near the fundamental absorption edge have been carried out at various temperatures. The room temperature energy gap is determined to be 0.54 eV. The temperature shift of the optical absorption edge in β‐HgS is +7.7 × 10 −4 eV/°K. With increasing carrier concentration, the absorption edge exhibits a shift to higher energies. The electron effective mass has been determined from reflectivity measurements. Its dependence on carrier concentration indicates nonparabolic behaviour of the conduction band. The temperature dependence of the electrical resistivity, Hall coefficient, and mobility between 4.2 and 300 °K has been measured. These studies reveal semimetallic behaviour of β‐HgS.