Simulation of Electronic Structure of Aluminum Phosphide Nanocrystals Using Ab Initio Large Unit Cell Method

Abstract

Ab initio restricted Hartree-Fock method coupled with the large unit cell method is used to determine the electronic structure and physical properties of aluminum phosphide (AlP) nanocrystals between 216 and 1000 atoms with sizes ranging up to about 3 nm in diameter. Core and surface parts with different sizes are investigated. Investigated properties include total energy, cohesive energy, energy gap, valence band width, ionicity, and degeneracy of energy levels. The oxygenated (001)-(1 × 1) facet that expands with larger sizes of nanocrystals is investigated to determine the rule of the surface in nanocrystals electronic structure. Results revealed that electronic properties converge to some limit as the size of the large unit cell increases and that the 216 core atoms approaches bulk of Aluminum phosphide material in several properties. Increasing nanocrystals size also resulted in a decrease in lattice constant, increase of core cohesive energy (absolute value), increase of core energy gap, increase of core valence band width and decrease of ionicity. Valence and conduction bands are wider on the surface due to splitting and oxygen atoms. The method also shows fluctuations in the converged energy gap, valence band width and cohesive energy of core part of nanocrystals duo to shape variation.

Electronic Structure of Hydrogenated and Surface-Modified GaAs Nanocrystals: Ab Initio Calculations

“…Figure 6 shows the variation of the lattice constant with the number of core atoms in LUC method. This (general) lattice reduction as nanocrystals grow up in size had been observed in all IV and some III-V semiconductors theoretically [10,11,13,14,17,19] and experimentally in diamond [20]. The increase of lattice constant between 8 and 16 atom LUC is due to shape effects since 8 atom LUC is a Bravais lattice while 16 atom LUC is a primitive lattice multiple [17].…”

Transport properties of binary phosphide AgP2 denoting high Hall mobility and low lattice thermal conductivity

“…First-principles calculations have been performed for AlP nanocrystals. Reportedly, the electronic properties approach those of bulk AlP as the nanocrystal size is increased [16].…”

Preparation of perovskite CsPb(BrxI1−x)3quantum dots at room temperature

“…1 As is well-known, both ion exchange and doping affect the electronic band structure. [2][3][4] Therefore, depending on the combination of these anions and cations, perovskite materials can exhibit different characteristics, such as superconductivity, piezoelectric, insulating, antiferromagnetic, and photoelectric properties. [5][6][7][8] So far, these nanomaterials have been demonstrated as promising building blocks for solar cells, exible sensors, and silicon-based photonics, and they are even expected to be used in biological detection and electrically driven lasers.…”