AbstractNanocolumn InGaN/GaN crystals were deposited on micropillared Si substrate by molecular beam epitaxy. Low‐temperature InN was used as interlayer. With enough free space, the column crystals grew around all the surface plane of the Si pillars and formed InGaN/GaN quantum‐well flower structure. The QW crystals are about 100 nm in diameter and 1.1‐1.4 μm in length. Raman spectra measurement of the fower structure shows that E2 mode peak line observed at 567.28 cm–1. Photoluminescence measurement indicates a room temperature PL peak position of 620 nm and two peak positions of 404 nm and 519 nm at temperature 15 K. Hg lamp excited photoluminescence demonstrated a clear fluorescence distribution in the flower structure and much stronger emission compared with the quantum‐well crystals on the flat Si substrate. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)