A computational approach to analyze grain structures of semiconductor compound films: Case study of CdTe/CdS multilayers

Abstract

Grain structures impact the performance of semiconductor devices. Molecular dynamics has been successfully applied to simulate the growth of semiconductor compounds, reproducing the experimentally observed complex zincblende and wurtzite grains. However, methodologies to characterize the simulated grain structures are still not mature, especially for semiconductors. This limits the usefulness of simulations in material optimization. In this work, the grain tracking algorithm originally developed by Panzarino et al. has been utilized to analyze the CdTe/CdS films obtained from molecular dynamics simulations. This work demonstrates that the parameters obtained from the polyhedral template matching algorithm in OVITO can be used to calculate the orientation of each grain. This provides a variety of useful information such as grain domains, grain orientations, plane indices, and sample texture. Moreover, dynamic analysis of microstructure evolution can be performed to understand grain growth mechanisms and kinetics. There are other useful features that are not included in the current tool such as identification and tracking of point defects (especially vacancies at grain boundaries). Nonetheless, the current approach is useful and our CdTe/CdS results provide input for further computational studies to relate grain structures to physical, chemical, mechanical, and electronic properties.