Preparation of P-type LaSe₂ films with conductivity and mid-infrared transparency by combining magnetron sputtering and selenized annealing

LaSe₂ films were prepared on sapphire (0001) substrates by combining magnetron sputtering and selenized annealing. The influence of selenized annealing time on the structures and photoelectric properties of the thin films were investigated using glancing incident X-ray diffraction, fourier transform infrared spectrometry and Hall effect measurements. The results showed that the film had a perfect monoclinic structure and a smooth surface morphology. The average transmittance in the mid-infrared range was greater than 55%, and the highest was 65%. The LaSe₂ films had a higher carrier concentration (∼10¹⁹ cm⁻³) and conductivity (∼1.9 S/cm) than those of other P-type transparent conductive films, which showed that LaSe₂ was a potential new P-type material.