Piezoelectric effects in GaN/AlGaN multiple quantum wells (MQWs) have been directly probed by picosecond time-resolved photoluminescence (PL) spectroscopy. The time-resolved PL spectra of the 40 angstrom well MQWs reveal that the PL transition peak position is in fact blueshifted at early delay times due to the collective effects of quantum confinement of carriers, piezoelectric field, and Coulomb screening. However, the spectral peak position shifts toward lower energies as the delay time increases and becomes redshifted at longer delay times. By comparing experimental and calculation results, we have obtained a low limit of the piezoelectric field strength to be about 560 kV/cm in the 40 angstrom well GaN/Al0.15Ga0.85N MQWs.
|Journal||Materials Research Society Symposium - Proceedings|
|State||Published - 1999|
|Event||Proceedings of the 1998 MRS Fall Meeting - Symposium on 'GaN and Related Alloys' - Boston, MA, USA|
Duration: Nov 30 1998 → Dec 4 1998