Strong influence of the humidity on the electrical properties of InGaAs surface quantum dots.
The impact of the environment on the electrical properties of uncapped In0.5Ga0.5As nanostructures is studied as a function of different atmospheres for sensing applications. Electrical response from surface quantum dots (QD) shows a strong dependence on the atmosphere, in contrast to the response of 2D nanostructures. The sheet resistance drops by 99% from vacuum to air, and decreases more than one order of magnitude when relative humidity changes from 0 to 70%. The adsorption of water molecules onto the QD surface improves the conductivity likely by reducing the density of surface states acting as carrier traps, which enhances electron transport.
Instituto de Sistemas Optoelectrónicos y Microtecnología (ISOM), Dpto. Ingeniería Electrónica, Universidad Politécnica de Madrid , Ciudad Universitaria s/n, 28040 Madrid, Spain.
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MJ
Milla
J M
JM
Ulloa
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Guzmán