Hexagonal Boron Nitride – Vapor Phase Growth, Templating, and Epitaxy of 2D Boron Sulfides

Two-dimensional materials like hexagonal boron nitride (h-BN) are highly relevant for applications due to their unique anisotropic structure, atomically flat layers, and exceptional mechanical and thermal stability. h-BN also acts as a template to enhance molecular order in organic semiconductors, improving organic electronics' performance. However, producing high-quality, large-area h-BN few-layers remains a significant challenge, particularly through chemical vapor deposition (CVD). This work investigated single-source precursors (SSPs) for h-BN synthesis on various substrates, optimizing deposition conditions to achieve high-quality thin films. A key achievement was the fabrication of few-layer h-BN on copper substrates using borazine (B3N3H6) in a hot-wall CVD reactor on a centimeter scale. These h-BN layers enabled the self-assembly of a linear organic molecule (P4F2, C24H16F2), forming cross-connected layers with six-fold symmetry across tens of micrometers. This templating effect minimizes charge losses and enhances the performance of electronic devices by inducing molecular order. Additionally, the synthesis and characterization of boron-sulfur molecular precursors with the general formula B(SR)3 (R = i-propyl, i-butyl, t-butyl, i-pentyl) were conducted, and their potential for forming boron sulfide (h-BS) and h-BN thin films was evaluated. Advanced characterization techniques, including Raman and FT-IR spectroscopy, SEM, EDX, and XPS, were used to analyze the chemical composition and morphology of the thin films. This study contributes to understanding the templating effects of 2D materials on organic molecular assembly and supports the development of high-performance organic electronic devices.