BaTiO3 perovskite for optoelectronics application: A DFT study

Parmar, Vandana B.; Raval, Dhara; Gupta, Sanjeev K.; Gajjar, P. N.; Vora, Aditya M.

doi:10.1016/j.matpr.2023.01.410

Cited by 4 publications

(2 citation statements)

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“…Therefore, we expect a larger experimental band gap for the doped h-BN. The resulting band gaps of doped h-BN are larger than the band gaps (0.5–1 eV) of ABC hexagonal hyper ferroelectric or the band gap of 2D ferroelectric In 2 Se 3 layer (0.78 eV by GGA-PBE) and are comparable to that of BaTiO 3 (1.56 eV obtained by GGA-PBE) . Here, it is worth mentioning that reduction of the band gap might cause leakage current during ferroelectric switching.…”

Section: Methodsmentioning

confidence: 73%

“…The resulting band gaps of doped h-BN are larger than the band gaps (0.5–1 eV) of ABC hexagonal hyper ferroelectric 28 or the band gap of 2D ferroelectric In 2 Se 3 layer (0.78 eV by GGA-PBE) 29 and are comparable to that of BaTiO 3 (1.56 eV obtained by GGA-PBE). 30 Here, it is worth mentioning that reduction of the band gap might cause leakage current during ferroelectric switching. However, leakage current is a common challenge for ferroelectric materials, for example, a large leakage current is observed in ferroelectric Sc-doped w-AlN.…”

Section: Methodsmentioning

confidence: 99%

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Engineering Ferroelectricity and Large Piezoelectricity in h-BN

Noor-A-Alam,

Nolan

2023

ACS Appl. Mater. Interfaces

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Hexagonal boron nitride (h-BN) is a well-known layered van der Waals (vdW) material that exhibits no spontaneous electric polarization due to its centrosymmetric structure. Extensive density functional theory (DFT) calculations are used to demonstrate that doping through the substitution of B by isovalent Al and Ga breaks the inversion symmetry and induces local dipole moments along the c-axis, which promotes a ferroelectric (FE) alignment over antiferroelectric. For doping concentrations below 25%, a “protruded layered” structure in which the dopant atoms protrude out of the planar h-BN layers is energetically more stable than the flat layered structure of pristine h-BN or a wurtzite structure similar to w-AlN. The computed polarization, between 7.227 and 21.117 μC/cm2, depending on dopant concentration and the switching barrier (16.684 and 45.838 meV/atom) for the FE polarization reversal are comparable to that of other well-known FEs. Interestingly, doping of h-BN also induces a large negative piezoelectric response in otherwise nonpiezoelectric h-BN. For example, we compute d 33 of −24.214 pC/N for Ga0.125B0.875N, which is about 5 times larger than that of pure w-AlN (5 pC/N), although the computed e 33 (−1.164 C/m2) is about 1.6 times lower than that of pure w-AlN (1.462 C/m2). Because of the layered structure, the rather small elastic constant C 33 provides the origin of the large d 33. Moreover, doping makes h-BN an electric auxetic piezoelectric. We also show that ferroelectricity in doped h-BN may persist down to its trilayer, which indicates high potential for applications in FE nonvolatile memories.

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Section: Methodsmentioning

confidence: 73%