Effect of indium doping on the transient optical properties of GaN films

We have investigated the effects of In doping on the optical properties of GaN films grown by gas-source molecular-beam epitaxy. Time-resolved photoluminescence was carried out to study the transient optical properties of the epitaxial films. In comparison to the undoped GaN film, the spontaneous emission lifetime was prolonged from below 20 to 70 ps by doping with In. Under high-excitation density, stimulated emission was observed from both samples. The threshold excitation density was found to be reduced in the In-doped sample. These significant improvements of the optical properties are attributed to the effective suppression of the formation of the nonradiative recombination centers caused by a change of the growth kinetics induced by a small amount of In supplied during growth of the GaN films.

[1]  Y. Aoyagi,et al.  An Approach to Achieve Intense Photoluminescence of GaN , 1999 .

[2]  Guy Feuillet,et al.  Improved quality GaN grown by molecular beam epitaxy using In as a surfactant , 1998 .

[3]  Richard J. Molnar,et al.  Photoluminescence excitation spectroscopy of free-to-bound transitions in undoped GaN grown by hydride vapor phase epitaxy , 1998 .

[4]  Y. Aoyagi,et al.  Improvements of the Optical and Electrical Properties of GaN Films by Using In-doping Method During Growth , 1999 .

[5]  L. Pfeiffer,et al.  Gain Spectra and Stimulated Emission in Epitaxial (In,Al) GaN Thin Films , 1996 .

[6]  M. Asif Khan,et al.  Vertical‐cavity, room‐temperature stimulated emission from photopumped GaN films deposited over sapphire substrates using low‐pressure metalorganic chemical vapor deposition , 1991 .

[7]  R. Taylor,et al.  OPTICAL GAIN IN GAN EPILAYERS , 1998 .

[8]  M. C. Lee,et al.  Isoelectronic In-doping effect in GaN films grown by metalorganic chemical vapor deposition , 1998 .

[9]  Theodore J. Schmidt,et al.  STUDY OF SURFACE-EMITTED STIMULATED EMISSION IN GAN , 1997 .

[10]  John F. Muth,et al.  Absorption coefficient, energy gap, exciton binding energy, and recombination lifetime of GaN obtained from transmission measurements , 1997 .

[11]  Takashi Mukai,et al.  Superbright Green InGaN Single-Quantum-Well-Structure Light-Emitting Diodes , 1995 .

[12]  Reuter,et al.  Surfactants in epitaxial growth. , 1989, Physical review letters.

[13]  Shuji Nakamura,et al.  SUBBAND EMISSIONS OF INGAN MULTI-QUANTUM-WELL LASER DIODES UNDER ROOM-TEMPERATURE CONTINUOUS WAVE OPERATION , 1997 .