Study of Band gap of doped silicon nanocrystal

Abstract

Silicon nanowires (SiNWs) are attracting great interest as the most promising building blocks for future nanoscale electronic devices. Remarkable development has been achieved toward the goal of application of SiNWs in industry in the past decade. The small sizes of SiNWs make their electronic properties strongly dependent on growth direction, size, morphology and surface reconstruction. A well-known example is the size dependence of the electronic band gap width of SiNWs irrespective of wire direction. As the wire diameter decreases, the band gap of the nanowire widens and deviates from that of bulk silicon gradually. Moreover the orientations of the wire axis and the surface have a great effect on the electronic properties of SiNWs. In this work, systematic studies on the electronic structure of SNWs were conducted based on Effective mass approximation. In this paper the diameter of nanocluster through which nanowire are made is calculated and the size of nanocrystal depends on number of atoms present in the nanocrystal and after calculating the size of nanocrystel the band gap of silicon nanowires doped with little amount of aluminum is calculated. And after the calculation interesting finding are obtained it is found that the band gap decreases with increasing size of nanocrystel and the band gap that calculated is different from the bulk silicon. And it is also found that the band gap of doped silicon nanowire is different from bulk material.In this paper, systematic studies on the electronic properties of SiNWs were conducted based on tight binding scheme and parameters, we calculate the band gap energy of doped silicon nanowires by calculating the size of the nanocrystel of the nanowires.Also in this paper it is found that there is effect of temperature on the band gap of doped silicon nanowires.The results which are obtained in this calculation are in excellent agreement with the experimental results.