Variable Range Hopping in Hydrogenated Amorphous Silicon-Nickel Alloys

Abdelfattah Narjis, Abdelhamid El kaaouachi, Abdelghani Sybous, Lhoussine Limouny, Said Dlimi, Abdessadek Aboudihab, Jamal Hemine, Rachid Abdia, Gerard Biskupski

Laboratoire de Physique de la Matière Condensée, Faculté des Sciences et Techniques de Mohammadia, Département de Physique, Mohammedia, Morocco.
Laboratoire de Spectroscopie Hertzienne LSH, Batiment P5, Université des Sciences et Technologies de LilleI 59 655 Villeneuve d’Ascq Cedex France.
Research Group ESNPS, Physics Department, University Ibn Zohr, Faculty of Sciences, B.P 8106, Hay Dakhla, 80000 Agadir, Morocco.

DOI: 10.4236/jmp.2012.37070                

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-Si_1-yNi_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.

Keywords

Amorphous Silicon-Nickel Alloys a-Si_1-yNi_y:H; Variable Range Hopping Conductivity; Transport Phenomenon; Metal Insulator Transition

Conflicts of Interest

The authors declare no conflicts of interest.

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