Deep-level defects related to the emissive pits in thick InGaN films on GaN template and bulk substrates

作者：Sumiya Masatomo^*; Toyomitsu Naoki; Nakano Yoshitaka; Wang Jianyu; Harada Yoshitomo; Sang Liwen; Sekiguchi Takashi; Yamaguchi Tomohiro; Honda Tohru

来源：APL Materials, 2017, 5(1): 016105.

DOI：10.1063/1.4974935

We studied the emissive pits in InGaN films grown on compressive and strain-free GaN underlying layers. Pit density decreased with the full width at half maximum of omega(0002) of InGaN. The films grew on compressive and strain-free GaN underlying layers with spiral and step-flow modes, respectively. Carbon impurities accumulated inside the pits. Comparison of cathodoluminescence inside the pits and steady-state photocapacitance spectra showed that the energy level of the carbon impurities appeared at similar to 2.8 eV below the conduction band (E-c) for both types of pits. Deep-level defects at E-c - 2.4 eV resulting in green fluorescence emission were considered to originate from pits related to screw dislocations.

• 出版日期2017-1