Semipolar GaN films on patterned r-plane sapphire obtained by wet chemical etching

摘要

It is shown that u0002112¯2u0003-oriented GaN films can be achieved from r-sapphire patterned by chemicalnetching. Growth first occurs selectively from the inclined c-facet of sapphire, leading finally to anfully coalesced layer with u0002112¯2u0003 orientation. The structural and optical quality of these layers wasnassessed by x-ray diffraction, cathodoluminescence and photoluminescence measurements. Thenresults clearly show that the quality of u0002112¯2u0003 GaN on patterned r-sapphire is markedly improvednin comparison with u0002112¯2u0003 GaN on m-sapphire.