Electronic, Vibrational, Elastic, and Piezoelectric Properties of H‐, F‐Functionalized AlN Sheets

Abstract

Hexagonal monolayer AlN (h-mAlN) is an indirect wide-gap semiconductor and is attractive for use in optoelectronic devices. Herein, first-principles calculations are performed to study the electronic, vibrational, elastic, and piezoelectric properties of H and F-functionalized AlN sheets. The results indicate that the H-/ F-functionalized (FAlNH) and fully H-functionalized (HAlNH) sheets are thermodynamically and dynamically stable. FAlNH is a direct bandgap material while HAlNH is still an indirect one. The F(H) atoms in F(H)AlNH bonded with Al act as electron acceptors whereas the H atoms bonded with N are electron donors. Some vibrational modes of these two functionalized systems differ significantly although their structures are similar. Functionalization with the H and F atoms reduces the elastic constants considerably and alters the mechanical performances of both systems. The in-plane piezoelectric constants of the FAlNH (HAlNH) sheet increase (decrease) surprisingly to about three times (one-third) that of h-mAlN. However, the work functions of both systems are enhanced notably. The study provides useful information for modulating the intrinsic properties of h-mAlN for possible applications.

Numerical Evaluation of the Elastic Moduli of AlN and GaN Nanosheets

“…In turn, E sNS reported by Le [76] showed a good agreement (difference of about 4%) with the surface Young's modulus obtained by Peng et al [62], who performed their ab initio DFT calculations with the VASP code. These results were similar to E sNS evaluated by Kourra et al [63] and Lv et al [64], who used the VASP and QE codes, respectively.…”

“…The ab initio method requires only fundamental physical constants as input, making it appropriate for a small number of atoms as it consumes large amounts of computational resources. Jafaria et al [61], Peng et al [62], Kourra et al [63], and Lv et al [64] employed ab initio DFT calculations to evaluate the elastic properties of ANNSs. Tuoc et al [65] and Fabris et al [66] used the same method to study the elastic behavior of GaNNSs.…”

First-Principles Calculations of the Phonon, Elastic, and Thermoelectric Properties of a Ti2CO2 Monolayer

“…This indicates that Ti 2 CO 2 can resist deformation and has bitter rigidity, so it belongs to an incompressible material. ν of Ti 2 CO 2 is 0.31, smaller than those of AlN, FAlNH, and HAlNH . The bending modulus is important for 2D materials and has a great effect on potential flexible and stretchable electronic applications .…”

“…ν of Ti 2 CO 2 is 0.31, smaller than those of AlN, FAlNH, and HAlNH. 54 The bending modulus is important for 2D materials and has a great effect on potential flexible and stretchable electronic applications. 55 The D of graphene and MoS 2 are 1.2 and 9.61 eV, respectively.…”

On Decorating a Honeycomb AlN Monolayer with Hydrogen and Fluorine Atoms: Ab Initio and Experimental Aspects

“…Predictive first-principles calculations establish the structure and dynamic stability of mono-and multilayer structures of h-AlN [4][5][6][7]. Their modeling further extends to surface functionalization of h-AlN with hydrogen (H) [8][9][10] and fluorine (F) [11][12][13] atoms as a strategy to tune its respective structural and electronic properties. Of particular note for future device applications are the predictions that fluorinated h-AlN may exhibit enhanced piezoelectricity and semi-metallicity [12].…”