We report on the achievement of a two dimensional electron gas in completely undoped In0.75Al0.25As/In0.75Ga0.25As metamorphic quantum wells. Using these structures we were able to reduce the carrier density, with respect to reported values in similar modulation – doped structures, to about 2 ÷ 3´ 1011 cm-2 with mobilities of up to 2.15´ 105 cm2 (V s)-1. We found experimentally that the electronic charge in the quantum well is likely due to deep – level donor states in the In0.75Al0.25As barrier band gap, whose energy lies within the In0.75Ga0.25As/In0.75Al0.25As conduction band discontinuity. This result is further confirmed through a Poisson – Schrödinger simulation of the two dimensional electron gas structure
Two dimensional electron gas formation in undoped In0.75Ga0.25As/In0.75Al0.25As quantum well
CAVALLINI, ANNA;FRABONI, BEATRICE
2004
Abstract
We report on the achievement of a two dimensional electron gas in completely undoped In0.75Al0.25As/In0.75Ga0.25As metamorphic quantum wells. Using these structures we were able to reduce the carrier density, with respect to reported values in similar modulation – doped structures, to about 2 ÷ 3´ 1011 cm-2 with mobilities of up to 2.15´ 105 cm2 (V s)-1. We found experimentally that the electronic charge in the quantum well is likely due to deep – level donor states in the In0.75Al0.25As barrier band gap, whose energy lies within the In0.75Ga0.25As/In0.75Al0.25As conduction band discontinuity. This result is further confirmed through a Poisson – Schrödinger simulation of the two dimensional electron gas structureI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
