Hsiao, Ching-LienChing-LienHsiaoCHIH-CHUNG YANGChen, Li-Chyong et al.Li-Chyong et al.Chen2018-09-102018-09-10200800036951http://www.scopus.com/inward/record.url?eid=2-s2.0-41049098007&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/338999https://www.scopus.com/inward/record.uri?eid=2-s2.0-41049098007&doi=10.1063%2f1.2898214&partnerID=40&md5=768b668baa941d7d1685f0576d6de933High-phase-purity zinc-blende (zb) InN thin film has been grown by plasma-assisted molecular-beam epitaxy on r -plane sapphire substrate pretreated with nitridation. X-ray diffraction analysis shows that the phase of the InN films changes from wurtzite (w) InN to a mixture of w-InN and zb-InN, to zb-InN with increasing nitridation time. High-resolution transmission electron microscopy reveals an ultrathin crystallized interlayer produced by substrate nitridation, which plays an important role in controlling the InN phase. Photoluminescence emission of zb-InN measured at 20 K shows a peak at a very low energy, 0.636 eV, and an absorption edge at ∼0.62 eV is observed at 2 K, which is the lowest bandgap reported to date among the III-nitride semiconductors. © 2008 American Institute of Physics.Energy gap; Molecular beam epitaxy; Nitridation; Photoluminescence; Sapphire; X ray diffraction analysis; Zinc; High-phase-purity zinc-blende; Ultrathin crystallized interlayer; Thin filmsjournal article10.1063/1.28982142-s2.0-41049098007