  High quality InN nanoparticles are grown using atmospheric chemical vapour
deposition technique via a self-seeded catalytic approach in the temperature
range of 580 to 650 oC. In this temperature region, nucleation barrier of InN
is overcome by seeding the low density In nano-particles prior to the
introduction of reactive ammonia. Samples having increasing carrier density are
grown with the help of increasing growth temperature to understand its role in
optical phonon structure. Near resonance Raman spectra show complete different
phonon pictures as compared to those for the off-resonance spectra. A Raman
forbidden mode of B1(high), because of the possible breakdown of selection rule
in the near-resonance condition, is invoked for the first time. Intensity and
frequency of this mode strongly depend on the carrier concentration in the
sample. In off-resonance conditions, A1(LO) mode for the sample with high
carrier concentration is dominated by Fano interference rather than
plasmon-phonon coupling. Variation of intensity of the B1(high) mode is
correlated with band filling effect, which is substantiated by the luminescence
studies of the InN samples with different carrier concentration.
