Direct synthesis of electrical-conductivity-controlled boron-carbonitride films on SiO2 substrates

In this study, electrical-conductivity-controlled boron-carbonitride (BCN) films were synthesized directly on SiO2 substrates by using thermal chemical vapor deposition (TCVD) with solid mixtures containing polystyrene (PS) and ammonia borane. The BCN films had atomically smooth surfaces. The carbon content of the BCN films was simply controlled by modulating the weight of PS in the precursor mixture, which allowed the electrical conductivity of the BCN film to be controlled. In addition, we found that selection of an appropriate growth temperature determined the resulting semiconducting or metallic behavior of the BCN film.