1/f noise near the free surface of a semiconductor
  This paper describes the so-called 1/f noise generated within the depleted region below a free semiconducting surface. It was shown that there is a link between the 1/f noise, which can be controlled by the band-bending, and the very narrow energy states (E<<kT) located on the top surface and vanishing into the bulk region. Also, it was shown that the noise can be lowered when the band-bending is reduced. A quantitative description of this reduction was provided. This study considered the n-type semiconductor. 
Tomasz Blachowicz