High-quality thin film growth of the weak topological insulator BiSe on Si (111) substrates via pulsed laser deposition

In this work, we report the growth of high-quality BiSe thin films deposited on Si (111) substrates at different temperatures via pulsed laser deposition. We observe poor sample quality at a low substrate temperature (T-sub = 175 degrees C), and as the substrate temperature increases, the crystallinity of the samples increases. At a substrate temperature, T-sub = 250 degrees C, BiSe Raman modes (modes centered around 97.6 and 112.9 cm (-1)) start to emerge with less intensity and evolve with the increase in the substrate temperature and at T-sub = 325 degrees C closely match with that of single crystals. These modes correspond to the vibrations of Se-atoms from the Bi2Se3 quintuple layers and Bi-atoms from the Bi-bilayer. By carefully investigating the structural properties and the Raman modes of BiSe thin films at each substrate temperature, we provide an optimal condition to grow high-quality thin films of BiSe by pulsed laser deposition.

Automated summary

We investigated the growth of high-quality BiSe thin films on Si (111) substrates at different temperatures using pulsed laser deposition. The sample quality improved as the substrate temperature increased, with BiSe Raman modes emerging at a substrate temperature of 250 degrees C. The modes matched closely with those of single crystals at a substrate temperature of 325 degrees C. By studying the structural properties and Raman modes at each substrate temperature, we identified the optimal condition for growing high-quality BiSe thin films via pulsed laser deposition.