[1][2] Reaction of thulium metal with phosphorus: The dense phosphide film will prevent further reactions inside the metal.

After etching gallium arsenide, an epitaxial layer of thulium phosphide can be grown on the surface to obtain a TmP/GaAs heterostructure.

[3][4] The compound forms crystals of a cubic system, space group Fm3m.

[5] TmP crystallizes in a NaCl-type structure at ambient pressure.

[6] The compound is a semiconductor used in high power, high frequency applications and in laser and other photo diodes.