Nanoscale physics 

Local electron interaction with crystal defects in CdSexTe1-x (x=0.2) solid solution: ab initio approach 
Malyk O.P.1, Lisnykh D.O.1
1 Semiconductor Electronics Department, Lviv Polytechnic National University, Bandera Street, 12, Lviv - 79013, Ukraine. 
E-mail: omalyk@ukr.net

At present, the main method for increasing the efficiency of solar cells based on cadmium telluride is the using an additional absorbent layer created on the base of triple compounds of cadmium chalcogenides, in particular CdSexTe1-x. Therefore, the study of the quality of these absorbing layers is an actual application problem.
In the present paper, the estimation of the quality of the absorbing layer is carried out by analyzing of its kinetic properties. The description of the transport phenomena is carried out by combining two approaches: 1 – using of wave function and self-consistent potential which were determined from the first principles on the base of projector augmented waves (PAW), as implemented in the ABINIT code [1]; 2 – using the short-range principle to consider the charge carrier interaction with different types of crystal defects [2,3]. On the base of obtained wave function and self-consistent potential for solid solution CdSexTe1-x (x=0.2) in the framework of short-range scattering models the calculation of transition probabilities for electron interaction with eight types of point defects are presented. The transition matrix elements were obtained by integration over the unit cell. For crystals with impurity concentration 5.61015 51018 cm-3 the temperature dependences of electron mobility and Hall factor in the range 15 ÷ 1200 K are calculated. The theoretical curves obtained in the short-range approach differ qualitatively and quantitatively from those obtained within the long-range models in relaxation time approximation.

1.	Gonze X. et al Recent developments in the ABINIT software package // Comput. Phys. Commun.- 2016.- 205.-P. 106-131.
2.	Malyk O.P., Syrotyuk S.V. New scheme for calculating the kinetic coefficients in CdTe based on first-principle wave function // Comput. Mater. Sci.-2017.- 139. -P. 387–394.
3.	Malyk O.P., Syrotyuk S.V. The local electron interaction with point defects in sphalerite zinc selenide: calculation from the first principles // J. Electron. Mater.-2018.- 47-P. 4212–4218.