Catalyst-Free Growth of Two-Dimensional BC_<i>x</i>N Materials on Dielectrics by Temperature-Dependent Plasma-Enhanced Chemical Vapor Deposition

Abstract

Traditional methods to prepare two-dimensional (2D) B-C-N ternary materials (BC_<i>x</i>N), such as chemical vapor deposition (CVD), require sophisticated experimental conditions such as high temperature, delicate control of precursors, and postgrowth transfer from catalytic substrates, and the products are generally thick or bulky films without the atomically mixed phase of B-C-N, hampering practical applications of these materials. Here, for the first time, we develop a temperature-dependent plasma-enhanced chemical vapor deposition (PECVD) method to grow 2D BC_<i>x</i>N materials directly on noncatalytic dielectrics at low temperature with high controllability. The C, N, and B compositions can be tuned by simply changing the growth temperature. Thus, the properties of the as-made materials including band gap and conductivity are modulated, which is hardly achieved by other methods. A 2D hybridized BC₂N film with a mixed BC₂N phase is produced, for the first time, with a band gap of about 2.3 eV. The growth temperature is 580-620 °C, much lower than that of traditional catalytic CVD for growing BC_<i>x</i>N. The product has a p-type conducting property and can be directly applied in field-effect transistors and sensors without postgrowth transfer, showing great promise for this method in future applications.