Nonisovalent(GaN)_(1-x)(ZnO)_(x)alloys are more technologically promising than their binary counterparts because of the abruptly reduced band gap.Unfortunately,the lack of two-dimensional(2D)configurations as well as ...Nonisovalent(GaN)_(1-x)(ZnO)_(x)alloys are more technologically promising than their binary counterparts because of the abruptly reduced band gap.Unfortunately,the lack of two-dimensional(2D)configurations as well as complete stoichiometries hinders to further explore the thermal transport,thermoelectrics,and adsorption/permeation.We identify that multilayer(GaN)_(1-x)(ZnO)_(x)stabilize as wurtzite-like Pm-(GaN)_(3)(ZnO)_(1),Pmc2_(1)-(Ga N)_(1)(ZnO)_(1),P3m1-(GaN)_(1)(ZnO)_(2),and haeckelite C2/m-(GaN)_(1)(ZnO)_(3)via structural searches.P3m1-(GaN)_(1)(ZnO)_(2)shares the excellent thermoelectrics with the figure of merit ZT as high as 3.08 at 900 K for the p-type doping due to the ultralow lattice thermal conductivity,which mainly arises from the strong anharmonicity by the interlayer asymmetrical charge distributions.The p–d coupling is prohibited from the group theory in C2/m-(Ga N)_(1)(ZnO)_(3),which thereby results in the anomalous band structure versus Zn O composition.To unveil the adsorption/permeation of H^(+),Na^(+),and OH^(-)ions in AA-stacking configurations,the potential wells and barriers are explored from the Coulomb interaction and the ionic size.Our work is helpful in experimental fabrication of novel optoelectronic and thermoelectric devices by 2D(GaN)_(1-x)(ZnO)_(x)alloys.展开更多
Single oxygen diffusion event,the most favorable rate-limiting process of epitaxial Cu_(2)O oxide-island layerby-layer growth kinetics,may lead to oxygen defects due to thermomechanical coupling.However,the formation ...Single oxygen diffusion event,the most favorable rate-limiting process of epitaxial Cu_(2)O oxide-island layerby-layer growth kinetics,may lead to oxygen defects due to thermomechanical coupling.However,the formation rules of oxygen defects remain unclear,preventing the realization of controllable oxygen defects on oxide-island surfaces.Here,we utilize the first-principles method to investigate the formation rules of intrinsic oxygen defects in the surface layers of prototypical metal-oxide(Cu_(2)O)surfaces under thermomechanical coupling effects.We establish the thermodynamic phase diagram for oxygen-defect-modulated Cu_(2)O surfaces,enabling the prediction of the growth of oxide islands during Cu oxidation,which aligns closely with in-situ environmental transmission electron microscopy(ETEM)experiment observations.By exploring the strain-modulated phase diagrams,we propose a potential strategy for controlling the type and concentration of oxygen defects on oxide-island surfaces.Our findings provide an effective approach to theoretically understanding the oxidation process of metal surfaces,thus enabling the computational design of high-performance corrosion-resistant surfaces.展开更多
基金the National Natural Science Foundation of China(Grant No.11774416)the Fundamental Research Funds for the Central Universities(Grant Nos.2017XKZD08 and 2015XKMS081)+1 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(Grant No.KYCX202039)the Assistance Program for Future Outstanding Talents of China University of Mining and Technology(Grant No.2020WLJCRCZL063)。
文摘Nonisovalent(GaN)_(1-x)(ZnO)_(x)alloys are more technologically promising than their binary counterparts because of the abruptly reduced band gap.Unfortunately,the lack of two-dimensional(2D)configurations as well as complete stoichiometries hinders to further explore the thermal transport,thermoelectrics,and adsorption/permeation.We identify that multilayer(GaN)_(1-x)(ZnO)_(x)stabilize as wurtzite-like Pm-(GaN)_(3)(ZnO)_(1),Pmc2_(1)-(Ga N)_(1)(ZnO)_(1),P3m1-(GaN)_(1)(ZnO)_(2),and haeckelite C2/m-(GaN)_(1)(ZnO)_(3)via structural searches.P3m1-(GaN)_(1)(ZnO)_(2)shares the excellent thermoelectrics with the figure of merit ZT as high as 3.08 at 900 K for the p-type doping due to the ultralow lattice thermal conductivity,which mainly arises from the strong anharmonicity by the interlayer asymmetrical charge distributions.The p–d coupling is prohibited from the group theory in C2/m-(Ga N)_(1)(ZnO)_(3),which thereby results in the anomalous band structure versus Zn O composition.To unveil the adsorption/permeation of H^(+),Na^(+),and OH^(-)ions in AA-stacking configurations,the potential wells and barriers are explored from the Coulomb interaction and the ionic size.Our work is helpful in experimental fabrication of novel optoelectronic and thermoelectric devices by 2D(GaN)_(1-x)(ZnO)_(x)alloys.
基金supported by the National Natural Science Foundation of China(U2230402,T2325004).
文摘Single oxygen diffusion event,the most favorable rate-limiting process of epitaxial Cu_(2)O oxide-island layerby-layer growth kinetics,may lead to oxygen defects due to thermomechanical coupling.However,the formation rules of oxygen defects remain unclear,preventing the realization of controllable oxygen defects on oxide-island surfaces.Here,we utilize the first-principles method to investigate the formation rules of intrinsic oxygen defects in the surface layers of prototypical metal-oxide(Cu_(2)O)surfaces under thermomechanical coupling effects.We establish the thermodynamic phase diagram for oxygen-defect-modulated Cu_(2)O surfaces,enabling the prediction of the growth of oxide islands during Cu oxidation,which aligns closely with in-situ environmental transmission electron microscopy(ETEM)experiment observations.By exploring the strain-modulated phase diagrams,we propose a potential strategy for controlling the type and concentration of oxygen defects on oxide-island surfaces.Our findings provide an effective approach to theoretically understanding the oxidation process of metal surfaces,thus enabling the computational design of high-performance corrosion-resistant surfaces.
