CHARGE-STORAGE EFFECT OF VERTICALLY STACKED InAs NANODOTS EMBEDDED IN Al0.5Ga0.5As MATRIX

Authors describe the memory effect of vertically stacked InAs nanodots in the barrier layer of an Al0.5Ga0.5As/GaAs field-effect (FE) structure by comparing this effect with that of single-layer InAs nanodots in the same FE structure. These FE structures are grown by MBE, and Stranski-Krastanow islands are used for the InAs nanodots. The charge-storage effect of the nanodots is analyzed by C-V measurement and results in a hysteresis loop caused by stable electron trapping at nanodot potentials. The amount of "net" charge surviving at the stacked nanodots at 300 K is estimated to be approx 14 nC/cm2, whereas that at the single-layer nanodots is nearly zero. These C-V characteristics are in agreement with photoluminescence properties. 13 refs.