TITLE:
Variable Range Hopping in Hydrogenated Amorphous Silicon-Nickel Alloys
AUTHORS:
Abdelfattah Narjis, Abdelhamid El kaaouachi, Abdelghani Sybous, Lhoussine Limouny, Said Dlimi, Abdessadek Aboudihab, Jamal Hemine, Rachid Abdia, Gerard Biskupski
KEYWORDS:
Amorphous Silicon-Nickel Alloys a-Si1-yNiy:H; Variable Range Hopping Conductivity; Transport Phenomenon; Metal Insulator Transition
JOURNAL NAME:
Journal of Modern Physics,
Vol.3 No.7,
July
17,
2012
ABSTRACT: 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-Si1-yNiy: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 TC, 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 TC decreases with nickel content in the alloys.