Effect of structural parameters on InGaAs/InAlAs 2DEG characteristics

It is shown that superlattices or very thick buffer layers are not necessary to achieve high mobility in InGaAs/InAlAs 2DEG structures. However, an InAlAs buffer is required to prevent the formation of a sheet charge at the back interface of the InGaAs channel when it is grown directly on InP heated in an As flux. It is found that bulk InAlAs is not characterized by persistent photoconductivity (PPC) or carrier freezeout and that the transport properties of the two-dimensional electron gas (2DEG) structures are must less affected by cooling and illumination than comparable AlGaAs/GaAs structures.<
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