Variable Range Hopping in Hydrogenated Amorphous Silicon-Nickel Alloys (original) (raw)

On the insulating side of the metal-insulator transition (MIT), the study of the effect of low Temperatures T on the electrical transport in amorphous silicon-nickel alloys a-Si 1-y Ni y :H exhibits that the electrical conductivity follows, at the beginning, the Efros-Shklovskii Variable Range Hopping regime (ES VRH) with T −1/2. This behaviour showed that long range electron-electron interaction reduces the Density of State of carriers (DOS) at the Fermi level and creates the Coulomb gap (CG). For T higher than a critical value of temperature T C , we obtained the Mott Variable Range Hopping regime with T −1/4 , indicating that the DOS becomes almost constant in the vicinity of the Fermi level. The critical temperature T C decreases with nickel content in the alloys.