Si-doped porous GaN is fabricated by UV-enhanced Pt-assisted electrochemical etching and together with a low-temperature grown buffer layer are utilized as the template for InGaN growth. The porous network in GaN shows nanostructures formed on the surface. Subsequent growth of InGaN shows that it is relaxed on these nanostructures as the area on which the growth takes place is very small. The strain relaxation favors higher indium incorporation. Besides, this porous network creates a relatively rough surface of GaN to modify the surface energy which can enhance the nucleation of impinging indium atoms thereby increasing indium incorporation. It shifts the luminescence from 445 nm for a conventionally grown InGaN structure to 575 nm and enhances the intensity by more than two-fold for the growth technique in the present invention under the same growth conditions. There is also a spectral broadening of the output extending from 480 nm to 720 nm.
展开▼
