Effect of ionized impurities on electron tunneling in GaAs/AlGaAs triple quantum wells

Photoluminescence and electroreflectance measurements in Si delta-doped GaA s/Al0.35Ga0.65- As triple quantum wells are performed in order to study the effect of ionized impurities on electron tunneling. It is theoretically sh own that a thin quantum well with a delta-doping layer inserted between nar row and wide quantum wells of asymmetric double quantum wells enhances impu rity scattering rate significantly. Photoluminescence decay time is found t o decrease 30% at maximum compared with a sample without a delta-doping lay er. (C) 1999 Academic Press.