tailieunhanh - Báo cáo hóa học: " Patterned growth of InGaN/GaN quantum wells on freestanding GaN grating by molecular beam epitaxy"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Patterned growth of InGaN/GaN quantum wells on freestanding GaN grating by molecular beam epitaxy | Wang et al. Nanoscale Research Letters 2011 6 117 http content 6 1 117 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Patterned growth of InGaN GaN quantum wells on freestanding GaN grating by molecular beam epitaxy Yongjin Wang Fangren Hu Kazuhiro Hane Abstract We report here the epitaxial growth of InGaN GaN quantum wells on freestanding GaN gratings by molecular beam epitaxy MBE . Various GaN gratings are defined by electron beam lithography and realized on GaN-on-silicon substrate by fast atom beam etching. Silicon substrate beneath GaN grating region is removed from the backside to form freestanding GaN gratings and the patterned growth is subsequently performed on the prepared GaN template by MBE. The selective growth takes place with the assistance of nanoscale GaN gratings and depends on the grating period P and the grating width W. Importantly coalescences between two side facets are realized to generate epitaxial gratings with triangular section. Thin epitaxial gratings produce the promising photoluminescence performance. This work provides a feasible way for further GaN-based integrated optics devices by a combination of GaN micromachining and epitaxial growth on a GaN-on-silicon substrate. pAcs . Introduction It s of significant interest to conduct the fundamental research as well as the applied study on the epitaxial growth on patterned GaN-on-silicon substrate 1-9 . Commercial GaN-on-silicon substrates make this research feasible 10 and novel epitaxial structures can be generated with smooth facets and are free of etching damage. It can also provide a great potential for further integrated GaN optics devices by a combination of the epitaxial growth etching of GaN and silicon micromachining. Compared to other growth techniques the selective growth of GaN by molecular beam epitaxy MBE is relative difficult 11 12 . The substrate also impacts on the epitaxial growth. As the .