Effects of thermal, elastic, and surface properties on the stability of SiC polytypes

SiC polytypes have been studied for decades, both experimentally and with atomistic simulations, yet no consensus has reached on the factors that determine their stability growth. Proposed governing are temperature-dependent differences in bulk energy, biaxial strain induced through point defects, surface properties. In this work, we investigate thermodynamic of 3C, 2H, 4H, 6H density functional theory (DFT) calculations. The small energies between can lead to intricate changes energetic ordering depending computational method. Therefore, employ compare various DFT codes, i.e., vasp, cp2k, fhi-aims; exchange-correlation functionals, LDA, PBE, PBEsol, PW91, HSE06, SCAN, RTPSS; nine different van der Waals (vdW) corrections. At $T=0$ K, 4H-SiC is marginally more stable than 3C-SiC, further increases temperature by including entropic effects from lattice vibrations. Neither most advanced vdW corrections nor a significant effect relative polytype stability. We (0001) surfaces commonly exposed during epitaxial For Si-terminated surfaces, find 3C-SiC be significantly 4H-SiC. conclude difference energy likely driving force 3C-nucleation, whereas slightly favors 4H polytypes. order describe crystal growth correctly, it thus crucial take into account these effects.