ZnO epitaxy on (111) Si using epitaxial $Lu2O3$ buffer layers

We report the growth and characterization of single-crystalline, crack-free, epitaxial (0001) ZnO films on (111) Si substrates using intervening epitaxial $Lu2O3$ buffer layers. The epitaxial orientation relationships are $(0001)ZnO∥(111)Lu2O3∥(111)Si$ and $[12¯10]ZnO∥[1¯10]Lu2O3∥[11¯0]Si$⁠. X-ray diffraction and transmission electron microscopy reveal that the ZnO films have high structural quality and an atomically sharp $ZnO∕Lu2O3$ interface. Temperature-dependent photoluminescence measurements show optical properties comparable to ZnO single crystals. The films have a resistivity of $0.31Ωcm$⁠, an electron concentration of $2.5×1017cm−3$⁠, and a mobility of $80cm2∕V⋅s$ at room temperature. The epitaxial growth of ZnO on Si represents a significant step toward the integration of ZnO-based multifunctional devices with Si electronics.