Diamondoids and large unit cell method as building blocks of InAs nanocrystals: A density functional theory study

Indium Arsenide diamondoids are suggested in this work as building blocks of InAs nanocrystals. In addition, the large unit cell method is used to investigate size dependence of electronic properties of InAs nanocrystals by investigating larger nanocrystal sizes. Both methods are complementary in the number of atoms and particle sizes. All-electron density functional theory at the generalized gradient approximation level of Perdew, Burke and Ernzerhof (PBE) is used in present work combined with large unit cell and molecular structure optimization methods. Results show that energy gap and bond lengths generally decrease with shape and size fluctuations as the number of atoms increases. Bond lengths and tetrahedral angles of diamondoids show that InAs diamondoid molecules are the closest molecular structures to ideal zincblende structure. Electronic and structural properties are in a very good agreement with both previous experimental and theoretical results.