A transferable force field for CdS-CdSe-PbS-PbSe solid systems

Abstract

A transferable force field for the PbSe-CdSe solid system using the partially charged rigid ion model has been successfully developed and was used to study the cation exchange in PbSe-CdSe heteronanocrystals [A. O. Yalcin et al., “Atomic resolution monitoring of cation exchange in CdSe-PbSe heteronanocrystals during epitaxial solid-solid-vapor growth,” Nano Lett. 14, 3661–3667 (2014)]. In this work, we extend this force field by including another two important binary semiconductors, PbS and CdS, and provide detailed information on the validation of this force field. The parameterization combines Bader charge analysis, empirical fitting, and ab initio energy surface fitting. When compared with experimental data and density functional theory calculations, it is shown that a wide range of physical properties of bulk PbS, PbSe, CdS, CdSe, and their mixed phases can be accurately reproduced using this force field. The choice of functional forms and parameterization strategy is demonstrated to be rational and effective. This transferable force field can be used in various studies on II-VI and IV-VI semiconductor materials consisting of CdS, CdSe, PbS, and PbSe. Here, we demonstrate the applicability of the force field model by molecular dynamics simulations whereby transformations are initiated by cation exchange.

Elastic, Mechanical and Phonon Behavior of Wurtzite Cadmium Sulfide under Pressure

“…To keep the original form of the applied potential, we also ignored the shell-shell interactions during the present research, as in Reference [13]. Further, Table 1 lists the present potential parameters employed in our calculations, and further details about the parameterization procedure of this potential can be also found in Reference [13]. The cell parameters of w-CdS were assigned as a = 4.13 Å and c = 6.63 Å, as seen in Figure 1 which is visualized with VESTA 3.0 [27].…”

“…For more information and other conjectures, interested readers can see References [23][24][25][26]. A recent shell model-type interatomic potential [13] was employed in this work, which is originally derived from DFT calculations for the bulk properties of CdS, CdSe, PbS, and PbSe solid compounds as well as their mixed phases. To keep the original form of the applied potential, we also ignored the shell-shell interactions during the present research, as in Reference [13].…”

“…A recent shell model-type interatomic potential [13] was employed in this work, which is originally derived from DFT calculations for the bulk properties of CdS, CdSe, PbS, and PbSe solid compounds as well as their mixed phases. To keep the original form of the applied potential, we also ignored the shell-shell interactions during the present research, as in Reference [13]. Further, Table 1 lists the present potential parameters employed in our calculations, and further details about the parameterization procedure of this potential can be also found in Reference [13].…”

“…Contrary to the above applied methods and employed potentials of literature, we report for the first time the use of a recent shell model-type interatomic potential [13] to determine the mentioned high-pressure quantities of w-CdS with geometry optimization calculations. During our work, we considered the elastic constants, bulk modulus, shear modulus, and Young modulus, elastic wave velocities, mechanical stability conditions, and phonon properties of w-CdS under pressures between 0 GPa and 5 GPa at T = 0 K.…”

Enhanced van der Waals epitaxy via electron transfer enabled interfacial dative bond formation

“…The dative bond energy for CdTe-on-NbSe2 (1.3 eV/CdSe) is less than the standard Cd-Se bond strength of 2.7 eV/CdSe, deduced from the cohesive energy of wurtzite CdSe [25]. One may covert this value into an interfacial binding energy of 1.88 eV/CdTe at the CdTe-NbSe2 interface, which is, however, five times as large as that of 0.38 eV/CdTe at the CdTe-G interface.…”