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Optical analysis of dislocation‐related physical processes in GaN‐based epilayers
Author(s) -
Jiang DeSheng,
Zhao DeGang,
Yang Hui
Publication year - 2007
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200675604
Subject(s) - dislocation , materials science , doping , impurity , condensed matter physics , optoelectronics , crystallography , chemistry , physics , composite material , organic chemistry
In this paper, recent progresses in optical analysis of dislocation‐related physical properties in GaN‐based epilayers are surveyed with a brief review. The influence of dislocations on both near‐band edge emission and yellow luminescence (YL) is examined either in a statistical way as a function of dislocation density or focused on individual dislocation lines with a high spatial resolution. Threading dislocations may introduce non‐radiative recombination centers and enhance YL, but their effects are affected by the structural and chemical environment. The minority carrier diffusion length may be dependent on either dislocation density or impurity doping as confirmed by the result of photovoltaic spectra. The in situ optical monitoring of the strain evolution process is employed during GaN heteroepitaxy using an AlN interlayer. A typical transition of strain from compression to tension is observed and its correlation with the reduction and inclination of threading dislocation lines is revealed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)