Optical properties of m-plane GaN grown on patterned Si(112) substrates by MOCVD using a two-step approach

Nonpolar m-plane GaN layers were grown on patterned Si (112) substrates by metal-organic chemical vapor deposition (MOCVD). A two-step growth procedure involving a low-pressure (30 Torr) first step to ensure formation of the m-plane facet and a high-pressure step (200 Torr) for improvement of optical quality was employed. The layers grown in two steps show improvement of the optical quality: the near-bandedge photoluminescence (PL) intensity is about 3 times higher than that for the layers grown at low pressure, and deep emission is considerably weaker. However, emission intensity from m-GaN is still lower than that of polar and semipolar (1 100 ) reference samples grown under the same conditions. To shed light on this problem, spatial distribution of optical emission over the c+ and c− wings of the nonpolar GaN/Si was studied by spatially resolved cathodoluminescence and near-field scanning optical microscopy.

[1]  M. Reiche,et al.  Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes , 2000, Nature.

[2]  C. Q. Chen,et al.  Luminescence from stacking faults in gallium nitride , 2005 .

[3]  Sebastian Metzner,et al.  Optical properties of nonpolar (1-100) and semipolar (1-101)GaN grown by MOCVD on Si patterned substrates , 2011, OPTO.

[4]  Hisashi Yamada,et al.  Effects of piezoelectric fields on optoelectronic properties of InGaN/GaN quantum-well light-emitting diodes prepared on nonpolar (1 0   0) and semipolar (1 1   2) orientations , 2009 .

[5]  Pierre Gibart,et al.  Epitaxial lateral overgrowth of GaN on Si (111) , 2003 .

[6]  Isamu Akasaki,et al.  Theoretical Study of Orientation Dependence of Piezoelectric Effects in Wurtzite Strained GaInN/GaN Heterostructures and Quantum Wells , 2000 .

[7]  S. Denbaars,et al.  Demonstration of Nonpolar m-Plane InGaN/GaN Light-Emitting Diodes on Free-Standing m-Plane GaN Substrates , 2005 .

[8]  C. Thomsen,et al.  Strain relaxation and strong impurity incorporation in epitaxial laterally overgrown GaN: Direct imaging of different growth domains by cathodoluminescence microscopy and micro-Raman spectroscopy , 1999 .

[9]  Naoki Shibata,et al.  m-Plane GaInN Light Emitting Diodes Grown on Patterned a-Plane Sapphire Substrates , 2009 .

[10]  Ü. Özgür,et al.  Low dislocation densities and long carrier lifetimes in GaN thin films grown on a SiNx nanonetwork , 2007 .

[11]  Hadis Morkoç,et al.  Nonpolar m-plane GaN on patterned Si(112) substrates by metalorganic chemical vapor deposition , 2009 .

[12]  A. Carlo,et al.  EFFECTS OF MACROSCOPIC POLARIZATION IN III-V NITRIDE MULTIPLE QUANTUM WELLS , 1999, cond-mat/9905186.

[13]  Wei Li,et al.  Comparative study of GaN/AlGaN MQWs grown homoepitaxially on (1 1 0 0) and (0 0 0 1) GaN , 2003 .

[14]  Sebastian Metzner,et al.  Epitaxial lateral overgrowth of non-polar GaN( 1 1̄ 0 0) on Si(1 1 2) patterned substrates by MOCVD , 2011 .

[15]  Sebastian Metzner,et al.  Optical studies of strain and defect distribution in semipolar (11¯01) GaN on patterned Si substrates , 2013 .