1/f conductance noise in n-type amorphous silicon

Abstract

We have measured conductance fluctuations in n-type hydrogenated amorphous silicon using current densities J in the range 0·1 < J < 0·55 A cm⁻² at various temperatures from 13°C to 170°C. The noise power density varies as 1/f from 2 H_z to 5 kH_z and increases as the square of the bias current at all temperatures studied as expected for flicker noise. The magnitude of the noise power increases with temperature and, if assumed to follow an Arrhenius curve, has an activation energy of 0·1 eV. For current densities exceeding about 1 A cm ⁻², we find large abrupt changes in the conductance superimposed on the flicker noise reminiscent of random telegraph noise.