Metallic Impurity-Activated Crystal Growth of Boron Phosphide by Chemical Vapor Deposition and Its Physical Properties

Needle single crystals of boron monophosphide as large as 5–100 μm in diameter and 4 mm in length were obtained by chemical vapor deposition on an impurity painted zone of quartz substrate at 1060–1120 °C. The impurities such as Mn, Ni, Pt, Ag or Au were painted on the substrate in a form of aqueous solution of their salts and decomposed or reduced to the respective metal in hydrogen atmosphere at 1000 °C. Needle crystals with the homo p-n junction were also prepared using Ni impurity. The colors of grown crystals varied with the change of gas composition. Differences of electrical resistivity and thermoelectric power were found between the crystals of different colors.