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[Display omitted] • This paper introduces four two-dimensional inorganic biphenylene-like structures based on ZnS and CdS. • Phonon dispersion and ab initio molecular dynamics (AIMD) simulations were used to demonstrate the dynamical and thermal stabilities. • All evaluated structures are ultra-wideband gap semiconductors, with band gap energy values from 3.59 to 5.34 eV. • p-BPN-ZnS demonstrated the highest Young modulus (Y x /Y y = 25.295/34.874 N/m), followed by p-BPN-CdS (Y x /Y y = 15.286/21.339 N/m). • Notably, b-BPN-ZnS displayed a particular characteristic, a negative Poisson ratio (ν x /ν y = -0.008/-0.030), being an auxetic material. This study presents four novel inorganic structures based on the biphenylene network (BPN): planar BPN-ZnS (p-BPN-ZnS) and BPN-CdS (p-BPN-CdS) and buckled BPN-ZnS (b-BPN-ZnS) and BPN-CdS (b-BPN-CdS). Cohesive energy analyses reveal that structural buckling enhances stability, and a perturbation is necessary to obtain planar lattices. Phonon dispersion and ab initio molecular dynamics (AIMD) simulations demonstrated the dynamical and thermal stabilities. ZnS-based structures exhibited more pronounced charge accumulation and depletion than CdS. All evaluated structures are ultra-wideband gap semiconductors, with band gap energy values of 4.33, 5.34, 3.59, and 4.30 eV (at HSE06 level) for p-BPN-ZnS, b-BPN-ZnS, p-BPN-CdS, and b-BPN-CdS, respectively. p-BPN-ZnS demonstrated the highest Young modulus (Y x /Y y = 25.295/34.874 N/m), followed by p-BPN-CdS (Y x /Y y = 15.286/21.339 N/m). On the other hand, b-BPN-ZnS and b-BPN-CdS exhibit lower Young Modulus, Y x /Y y = 4.135/14.709 and 11.842/8.218 N/m, respectively. Notably, b-BPN-ZnS displayed a particular characteristic, a negative Poisson ratio (ν x /ν y = -0.008/-0.030), being an auxetic material. This report is expected to stimulate both theoretical and experimental researchers in the prediction and development of new inorganic materials based on the biphenylene network. [ABSTRACT FROM AUTHOR]

[Display omitted] Metal-halide perovskites, particularly inorganic cesium-lead halide perovskites, have emerged as exceptional candidates for several technological applications in the 21st century, such as photovoltaic devices, optoelectronic and photocatalysis. This study systematically investigates the CsPbI 3 surfaces through density functional theory (DFT) simulations and morphological analyses. The (0 0 1), (1 1 0), and (1 1 1) surfaces were investigated in terms of their possible terminations (here named α , β , γ , δ and ε), where the relations between their outermost coordination polyhedra, bond lengths, charge distribution, electronic and morphological properties were revealed. The results demonstrate that the (0 0 1) and (1 1 0) surfaces stand out as the most stables, with E s u r f 001 - α = E s u r f 110 - γ = 0.08 J / m 2. Concerning the electronic properties, it is observed that the (1 1 0) and (1 1 1) present α terminations with acceptor states, while the β with donor states, making it possible to tune the system semiconducting behavior (n or p-type) via surface termination control. The Wulff construction was employed to show that (0 0 1), (1 1 0) and (1 1 1) surface stabilizations can produce cubic, dodecahedral and octahedral nanocrystal morphologies, respectively. By probing the depths of CsPbI 3 surfaces, this research advances new concepts about the design and functionalization of perovskite halide, offering a crucial direction for experimental synthesis strategies. [ABSTRACT FROM AUTHOR]

[Display omitted] • The paper introduces a novel two-dimensional inorganic inorganic graphenylene based on indium nitride (IGP-InN). • The material demonstrates dynamic and thermal stability at elevated temperatures (700 K) and exhibits competitive cohesive energy compared to its hexagonal InN counterpart. • An indirect band gap transition with energy (E gap) of 2.49 eV was noted, making IGP-InN suitable for optoelectronic applications in the UV visible. • An accentuated decrease in the E gap can be noted for tensile strains, with a variation of 1.19 eV. • A transition to a planar structure at tensile strains higher than 4% was observed, and a new symmetry (P 6/ m) was found. This paper reveals the structural, electronic and mechanical properties of a novel inorganic graphenylene based on indium nitride (IGP-InN). The IGP-InN was characterized via density functional theory (DFT) simulations. The phonon dispersion shows the dynamic stability of IGP-InN, and molecular dynamics simulations confirm its thermal stability up to 700 K. Besides the electronic properties, the indirect band gap transition with energy (E gap) of 2.49 eV makes IGP-InN suitable for optoelectronic applications under UV–visible. Also, the E gap tunability with mechanical strain was analyzed, with a decrease of 1.19 eV in the E gap for tensile strains. The structural buckling plays an important role, with a transition to a planar structure for tensile strains. This work reveals a new class of 2D materials, buckled inorganic graphenylenes, and provides valuable insights into designing and optimizing graphenylene-like materials. [ABSTRACT FROM AUTHOR]

In recent years, several atomically thin two-dimensional (2D) materials have been reported with remarkable properties that prospect them as potential structures for nanotechnological applications. Advancing the research of layered structures, in this work, a new 2D inorganic material based on germanium carbide (GeC) and characterized by 4-, 6- and 12-membered rings, named inorganic graphenylene-like germanium carbide (IGP-GeC), is proposed via density functional theory (DFT) simulations to predict its structural, electronic, and mechanical properties. This structure has a direct band gap energy (2.65 eV), which can be modulated from 3.39 eV to a conductor character by applying a biaxial strain (ε) from −12% to 12%, making it a promising contender for nanoelectronics applications. IGP-GeC has an in-plane dielectric constant of 7.15 that increases with tensile strain, reaching 10.51 (ε = 12%), an exciting result in comparison with other 2D materials, also leading to remarkable excitonic properties in both unstrained and strained conditions. Besides this, the effective masses analysis denotes great stability of the charge carriers for IGP-GeC, improved by the tensile strain application. Finally, molecular dynamics (MD) simulations show that IGP-GeC is stable at 1200 K, and the absence of imaginary modes in the phonon bands attests to the dynamical stability of this novel 2D material, which will be useful to experimentalists in further studies. [Display omitted] • Inorganic graphenylene-like germanium carbide (IGP-GeC) is a new 2D material with mechanical, thermal and dynamical stability. • IGP-GeC has a central ring diameter of 7.18 Å, being possible the improvement of ions and molecules interacting with the nanosheet. • Having a bang gap energy of 2.65 eV, IGP-GeC characterizes as a semiconductor in the visible range of light. • Under biaxial strain engineering, the gap energy of IGP-GeC varies from 3.39 eV to metallic behavior. • The electron-hole recombination observed for IGP-GeC makes it a 2D material with promising excitonic properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • r-GeO 2 NPs with cubic, octahedral or hexadecahedral morphologies can have photocatalytic activity for H 2 production. • The optoelectronic properties of r-GeO 2 -systems can be significantly altered via morphological control. • The surface stability order (1 1 0) > (1 0 0) > (3 2 1) > (3 1 1) > (2 0 1) > (2 1 1) > (1 0 1) > (1 0 3) > (0 0 1) > (1 1 1) was observed. • Non-conventional planes also can exhibit promising properties, which can open perspectives of experimental studies. Recently, the knowledge of surface-dependent properties has attracted a lot of attention since it is crucial for materials functionalization based on the morphological control of nanoparticles (NPs). This study describes the surface-dependent properties and morphological transformation routes of rutile germanium dioxide (r-GeO 2) using the density functional theory (DFT) and the Wulff construction procedure. The calculations revealed the following order of relative surface stability: (1 1 0) > (1 0 0) > (3 2 1) > (3 1 1) > (2 0 1) > (2 1 1) > (1 0 1) > (1 0 3) > (0 0 1) > (1 1 1), with the Ge-O bonds being attributed to G e 4 p - O 2 p and G e 4 s - O 2 p interactions. The results demonstrate that the different coordination breakages on the outermost polyhedra are related to atomic charges, band gap, relative stability, and Fermi energy. Additionally, a map of the morphological transformation routes and the band alignment were elaborated, showing that cubic, octahedral, or hexadecahedral morphologies can have photocatalytic activity for H 2 production via water splitting. The methodology and results reported herein can help target the synthesis and functionalization of rutile-type materials. [ABSTRACT FROM AUTHOR]

• The alloy nanotubes have low junction energy and good interaction between them. • The charge in the alloy nanotubes can induce the adsorption of different molecules. • With the tensile strain, the E gap decreases while the piezoelectricity increases. • The emission in the electromagnetic spectrum is altered by junction and strain. Nanotubes have become the focus of interest in recent years because of their unique properties that make them natural candidates for many devices. The junction of two different nanotubes can form alloys imparting new properties or enhance existing properties associated with one or both starting materials. The present study aims to investigate the properties of aluminum and gallium nitride (AlN and GaN, respectively) single- and double-walled nanotubes and double-walled alloy nanotubes (Al 0.5 Ga 0.5 N and Ga 0.5 Al 0.5 N) by using the density functional theory (DFT). It is observed that the emission of single-walled nanotubes (SWNT) changes from deep-UV to the blue region of the electromagnetic spectrum for double-walled GaN nanotubes (DWGaN). For the alloy nanotubes, the emission occurs at UVA and UVB regions for Al 0.5 Ga 0.5 N and Ga 0.5 Al 0.5 N, respectively. Also, the impact of the applied mechanical strain is investigated for all nanotubes. It is observed that with tensile strain, the band gap energy decreases while the piezoelectricity increases. Of all the zigzag nanotubes investigated, SWAlN, DWAlN, and the Al 0.5 Ga 0.5 N alloy nanotube exhibit larger piezoelectric constants. The analysis of electron density revels that the alloy nanotubes can be used to fabricate a selective dual gas sensor and that the functionalization, using an interface or by the application of strain, can be used to modulate the properties of materials. [ABSTRACT FROM AUTHOR]