Far-Infrared Magneto-Optical Investigation of p-Black Phosphorus in Pulsed High Magnetic Fields

Abstract

Systematic cyclotron resonance measurements have been performed on p-type black phosphorus in high pulsed magnetic fields up to 40 T using an optically pumped far-infrared laser. A new resonance peak has been observed in addition to the usual hole cyclotron resonance. It was found that there was a small portion of n-type crystals in some p-type samples. By considering this fact of coexistence of n- and p-type regions, a possible mechanism of doping in black phosphorus is proposed. The temperature coefficients of the effective masses of holes have been determined for the first time over a wide temperature range between 30 K and 220 K, in magnetic fields parallel to the a, b and c axes.