High-efficiency light-emitting column-crystallized InGaN∕GaN quantum-well flower structure on micropillared Si substrate

Column-crystallized InGaN∕GaN quantum-well flower structure was deposited on pillared Si (111) substrate. Dotted GaN nuclei grew along the direction of the coming Ga and N atoms, forming arrays of InGaN∕GaN quantum-well flower structure. Raman spectra measurement demonstrated that these crystals were fully relaxed. Photoluminescence measurement showed a room temperature peak position of 556nm and two peak positions of 400 and 549nm at low temperature. Hg lamp excited photoluminescence demonstrated a clear fluorescence distribution from the low to the top part of the flower structure and much stronger emission compared with the quantum-well crystals on the flat Si substrate.