Yd. Jho et al., Measurement of piezoelectric field and tunneling times in strongly biased InGaN/GaN quantum wells, APPL PHYS L, 79(8), 2001, pp. 1130-1132
We have measured both spectrum- and time-resolved photoluminescence (PL) of
InGaN/GaN light-emitting diode structure as a function of an external bias
. From spectrum-resolved PL, we observed regions of blueshift and redshift
in peak PL energies. From the bias point at which redshift begins, which we
attribute to the inversion of electric field due to full compensation of t
he piezoelectric field (PEF), we estimate PEF to be 2.1+/-0.2 MV/cm. From t
ime-resolved PL, we found the carrier lifetimes to drastically decrease (2.
5 ns-2 ps) with increasing reverse bias. We attribute this decrease to esca
pe tunneling through tilted barriers. (C) 2001 American Institute of Physic
s.