CVD growth of layered Cr2O3 hexagonal flakes for optoelectronic applications

Abstract Chromium (III) oxide (Cr2O3) is a unique material which possesses a layered structure in the corundum structure phase, quite similar to the graphene and other transition metal dichalcogenides (TMDCs). Systematically, layered 2D-Cr2O3 hexagonal flakes were synthesized by chemical vapor deposition (CVD) method with Iodine as an assisting material. Under the controlled conditions (temperature, N2:H2 in carrier gas, etc), Iodine is playing a key role in transforming the crystal structure into hexagonal phase and grows in the form of layers. Incident light polarization dependent Raman spectroscopy was employed to see the coupling of in-plane Eg mode with spin to predict the anti-ferromagnetic ordering of spin in Cr2O3 hexagonal flake. Due to layer stacking and ordering, strong feature of creation of magnon states has been observed in photoluminescence (PL) spectroscopy. Finally, photo-detector response was measured to test the stability and reliability of the as-grown flakes for their use in spintronic devices.