Hole and electron traps at a p-n heterostructure with InGaAs/GaAs quantum d
ots (QD) grown by metal organic chemical vapor deposition (MOCVD) are inves
tigated by capacitance-voltage (C-V) and deep level transient spectroscopy
(DLTS). The C-V and DLTS measurements allowed to detect that the region of
the accumulation of the electron concentration is characterized by the pres
ence of hole and electron traps. We have observed by means of deep level de
fects, the population of the energy states of InGaAs quantum dots as a func
tion of temperature of isochronous annealing as well as under bias-on-bias-
off cooling conditions and white light illumination. (C) 1999 Elsevier Scie
nce B.V. All rights reserved.