Bi[Se-(2-Me2NC6H4)]3: Single Source Precursor for Preparing Pure-Phase, 2-Dimensional Bismuth Selenide Films

Chemical vapor deposition using molecular compounds is a salient method to achieve high-quality, uniform films comprising two-dimensional flakes. In this communication, we present the synthesis and characterization of analytically pure single crystals of Bi[Se-(2-Me₂NC₆H₄)]_3, used as a single source precursor to grow thin films of bismuth selenide. The structural and morphological studies of the films were performed using powder X-ray diffraction, Raman spectroscopy, scanning, and transmission electron microscopy, revealing a pure phase stoichiometry with two-dimensional flakes of quintuple layers grown on glass, Si, and sapphire substrates. The deposited films on the glass surface show a near-ideal Bi to Se stoichiometry of 1.84 and exhibit an ambient temperature resistivity of 30 mΩ.cm. When unevenly illuminated with a laser of 532 nm wavelength, it shows a photo-thermoelectric (PTE) voltage generation with a response time of 2 seconds and an estimated Seebeck coefficient value of −128±6.6 μV/K, thus demonstrating its suitability for device applications in IoTs.