The screening of a potential of charged centers by quasi-two-dimensional electrons in transverse electric field

We propose a novel structure for a gas-sensitive element based on the change in the conductivity of ultra-thin, quantum-size semiconductor film caused by scattering of free carriers with charged ions of gas particles adsorbed on the surface of the film. To find a contribution of such scattering to the mobility, we have found the potential of adsorbed ions taking into account the screening effect of two-dimensional electron gas and the shift of electron distribution in the quantum-size film under the influence of average electric field of adsorbed surface charges. The mobility dependence on adsorbed gas particle surface density is different for positive and negative ions. q2000 Elsevier Science B.V. All rights reserved.