Epitaxial growth of nonpolar ZnO and n-ZnO/i-ZnO/p-GaN heterostructure on Si(001) for ultraviolet light emitting diodes

Nonpolar a-plane ZnO-film and n-ZnO/i-ZnO/p-GaN heterostructure LEDs were grown epitaxially by pulsed laser deposition and metal-organic chemical vapor deposition on Si(001) using AlN and MnS as buffer layers. X-ray diffraction pole figures showed an epitaxial relationship of ZnO() AlN() MnS(001) Si(001). A near band-edge emission from ZnO was observed at 378 nm in photoluminescence measurements. Electroluminescence of nonpolar n-ZnO/i-ZnO/p-GaN LEDs displayed UV emission at 390 nm under forward and reverse bias. Successful growth of nonpolar n-ZnO/i-ZnO/p-GaN heteroepitaxial on Si provides an attractive solution for integrating nonpolar ZnO-based optoelectronic devices with Si substrates for various applications.