Growth and Abnormal Luminescence Behavior of InN on InGaN Bedding Layer by Metalorganic Chemical Vapor Deposition

Epitaxial growth of InN film by metalorganic chemical vapor deposition (MOCVD) is investigated with adding an InGaN bedding layer. The structure and optical properties of the InN film are in-vestigated by transmission electron microscopy (TEM) and photoluminescence (PL). From the se-lective area electron diffraction pattern in the TEM, the InN is found to be almost strain free. At low temperature of 8 K, strong PL of the InN film indicate that the energy band gap of the InN is about 0.75 eV. The anomalous persistent PL decay behavior under continuous-wave excitation has been observed and discussed as the surface recombination and strong surface/interface effect of the InN film. These results indicate that suppressing and eliminating surface/interface states is one of the key factors in enhancing the performance of the InGaN-based long-wavelength optoe-lectronic devices, which is significant for the development of efficient long-wavelength (red and beyond) InGaN or InN devices.