Nanoscale Physics

The electronic structure of doped crystals Si<B, T> (T=Fe, Co, Ni) under strong correlation effect 

Syrotyuk S. V.1, Khoverko Yu. M.1,2, Shcherban N. O.1, Druzhinin A.A.1,2 

1 Semiconductor Electronics Department, Lviv Polytechnic National University, 
S. Bandera str., 12, Lviv-79013, Ukraine. 
2 Institute of Low Temperature and Structure Research PAS, Wroclaw, Poland
E-mail: svsnpe@gmail.com

	Investigation of semiconductors with transition metal impurities has attracted a lot of attention in the few last years. For example, in the paper [1] the magnetoresistance of Si whiskers, doped with Ni and B elements, has been studied. The electronic structure of Si crystal with transition metal impurities has been evaluated within the GGA approach on PAW basis states [2].
 Here we evaluate the electronic structure taking into account the strong correlated 3d electrons of transition element. We calculated the electronic energy bands and density of states in the crystal supercells Si30B1Fe1, Si30B1Co1 and Si30B1Ni1. The results obtained here for the crystal Si30B1Co1 are shown in Fig. 1. 

Fig. 1. The density of states in the crystal Si30B1Ni1 evaluated with hybrid exchange-correlation functional PBE0. 

As can be seen from Fig. 1 the crystal Si30B1Ni1 is a semiconductor. Taking into account the strong correlations of Co 3d electrons () resulted in an increase in the band gap width.

1.	Druzhinin A., Ostrovskii I., Khoverko Yu., Yatsukhnenko S. Magnetic properties of doped Si <B, Ni> whiskers for spintronics // J.Nano Res.-2016.-39.-P. 43-54.
2.	Zhang Z.Z., Portoens B., Kai Chang, Peeters F.M., First-principles study of transition metal impurities in Si // Phys. Rev. B. -2008.-77, 155201.-P. 1-8.