Metal halide perovskites,owing to their remarkable optoelectronic properties and broad application prospects,have emerged as a research hotspot in materials science and photovoltaics.In addressing challenges related t...Metal halide perovskites,owing to their remarkable optoelectronic properties and broad application prospects,have emerged as a research hotspot in materials science and photovoltaics.In addressing challenges related to energy loss,photoelectric conversion efficiency,and operational stability in perovskite solar cells(PSCs),various strategies have been proposed,such as improving perovskite crystallization,developing tandem architectures,and advancing interfacial engineering.However,the specific impact of these approaches on internal energy transfer and conversion mechanisms within PSCs remains insufficiently understood.This review systematically examines the relationship between energy and perovskite materials throughout the photon absorption to charge carrier transport process,with particular focus on key strategies for minimizing energy losses and their underlying influence on energy-level alignment-especially in the electron transport layer and hole transport layer.It summarizes optimal absorption conditions and contributing factors during energy transfer,alongside representative case studies of high-performing systems.By elucidating these mechanisms,this work offers valuable theoretical insights for optimizing energy-level alignment,reducing energy dissipation,and guiding experimental design in PSCs research.展开更多
In this paper, we find the invariant eigen-operators （IEOs） and the energy-level gap of a system with a two-level atom interacting with single mode cavity field through multi-photon transition in the presence of a K...In this paper, we find the invariant eigen-operators （IEOs） and the energy-level gap of a system with a two-level atom interacting with single mode cavity field through multi-photon transition in the presence of a Kerr-like medium. From this work, one can see that the IEO method in many eases is simpler and easier on obtaining the energy-level gap formula than the usual way.展开更多
We investigate the energy-level shift of a hydrogen atom in a two-dimensional optical microcavity, where there exists a Bose-Einstein condensation of photons. It is found that below the critical temperature Tc, the en...We investigate the energy-level shift of a hydrogen atom in a two-dimensional optical microcavity, where there exists a Bose-Einstein condensation of photons. It is found that below the critical temperature Tc, the energy-level shift of the bound electron is dependent on temperature, and it is a monotonically increasing function of the absolute temperature T. Especially, at the absolute zero temperature, the energy-level shift entirely comes from the Lamb shift, and the atom can be treated approximately, that is, in vacuum.展开更多
We propose aΛ-type superconducting three-energy-level device-based communication system for extremely weak microwave communication scenarios,for example,long-distance deep-space communication.We provide a system diag...We propose aΛ-type superconducting three-energy-level device-based communication system for extremely weak microwave communication scenarios,for example,long-distance deep-space communication.We provide a system diagram and propose the frame synchronization and power estimation approaches based on pre-defined synchronization sequences.Based on the microwave response characteristics of the superconducting three-energy-level system,we further investigate the optimization of synchronization sequence and information symbol modulation.We show that three-energy-level systems with weak Markovianity can be approximated using independent identical distribution methods to obtain optimal synchronization sequences,and the optimal modulation is asymmetric.The proposed system design and optimization approaches are evaluated by numerical results.Moreover,we investigate the performance of the three-energy-level communication system in the presence of interference.Simulation results show that the three-energy-level communication system can tolerate more than 10 dB interference compared to long term evolution(LTE)systems and achieve the same communication rate for the same bandwidth and temperature.展开更多
Different definitions for chiral doublet bands based on excitation energies, B(E2) and B(M1) respectively are discussed in the triaxial particle rotor model. For the ideal chiral geometry, the selection rules of the e...Different definitions for chiral doublet bands based on excitation energies, B(E2) and B(M1) respectively are discussed in the triaxial particle rotor model. For the ideal chiral geometry, the selection rules of the electromagnetic transitions in different band definitions are illustrated. It is also shown that the energy-level crossings between chiral doublet bands may occur.展开更多
Some important insights into the electron-states-architecture (ESA) and its dimensionality (from 3 to 0) in a semiconductor (or generally crystalline) material are obtained. The self-consistency of the set of density ...Some important insights into the electron-states-architecture (ESA) and its dimensionality (from 3 to 0) in a semiconductor (or generally crystalline) material are obtained. The self-consistency of the set of density of states (DOS) expressions with different dimensionalities is remediated through the clarification and rearrangement of the wave-function boundary conditions for working out the eigenvalues in the wave vector space. The actually too roughly observed and theoretically unpredicted critical points for the dimensionality transitions referring to the integer ones are revealed upon an unusual assumption of the intrinsic energy-level dispersion (ELD). The ELD based quantitative physical model had been established on an immediate instinct at the very beginning and has been properly modified afterwards. The uncertainty regarding the relationship between the de Broglie wavelength of electrons and the dimensionality transitions, seeming somewhat mysterious before, is consequentially eliminated. The effect of the material dimensions on the ELD width is also predicted and has been included in the model. The continuous evolution of the ESA dimensionality is convincingly and comprehensively interpreted and thus the area of the fractional ESA dimensionalities is opened. Another new assumption of the spatial extension shrinkage (SES) closely related to the ELD has also been made and thus the understanding of the behavior of an electron or, in a general sense, a particle has become more comprehensive. This work would manifest itself a new basis for further development of nanoheterostructures (or low dimensional heterostructures including the quantum wells, quantum wires, quantum dots and especially the hetero-dimensional structures). Expected should also be the possible inventions of some novel electronic and optoelectronic devices. More basically, it leads to a new quantum mechanical picture, the essential modifications of Schrödinger equation and Newtonian equation that give rise to a full cosmic-scope picture, and a super-low-speed relativity assumption.展开更多
Using the multi-configuration Dirac-Fock self-consistent field method and the relativistic configuration interaction method with quantum-electrodynamics corrections performed by the GRASP code, we calculate the fine-s...Using the multi-configuration Dirac-Fock self-consistent field method and the relativistic configuration interaction method with quantum-electrodynamics corrections performed by the GRASP code, we calculate the fine-structure energy levels of the ground-state configuration （1s^22s^22p^3） of the nitrogen isoelectronic sequence, according to the L-S coupling scheme with atomic number Z up to 22. Based on the calculated results, we elucidate the mechanism of the orderings of fine-structure energy levels of 2^ D3/2,5/2 and 2^P1/2,3/2 respectively, i.e. for 2^D3/2,5/2 orderings, the competition between the spin-orbit interactions and the Breit interactions; for 2^P1/2,3/2 orderings, the electron correlations, especially the electron correlations owing to the 2p^5 configuration interactions.展开更多
Nanorod is a unique low-dimensional nanometer structure in which the Landau level arrangement of polaron is essential for understanding its quasiparticle system.However,the stability of the polaron level is susceptibl...Nanorod is a unique low-dimensional nanometer structure in which the Landau level arrangement of polaron is essential for understanding its quasiparticle system.However,the stability of the polaron level is susceptible to external factors,such as changing magnetic fields.In this manuscript,the Pekar variational method is employed to calculate the external magnetic field's effect on the nanorod's polaron Landau level.It was found that different magnetic fields have different effects on the polaron energy levels of the nanorod,which demonstrated that the external environment had critical effects on the polaron energy levels.This study provides a theoretical basis for regulating the interaction between electrons and phonons in low-dimensional nanomaterials.展开更多
By using Gumming （JC） model. energy-level gap of this the pseudo invariant eigen-operator method we The pseudo-invariant eigen-operator is found in JC Hamiltonian is derived. This approach seems analyze the field-in...By using Gumming （JC） model. energy-level gap of this the pseudo invariant eigen-operator method we The pseudo-invariant eigen-operator is found in JC Hamiltonian is derived. This approach seems analyze the field-intensity-dependent Jaynes terms of the supersymmetric generators. The concise.展开更多
Multi-peak structures in photoluminescence spectra of InAs/GaAs quantum dots are investigated. Excitation power-dependent photoluminescence spectra are used to identify the nature of different peaks. By combining expe...Multi-peak structures in photoluminescence spectra of InAs/GaAs quantum dots are investigated. Excitation power-dependent photoluminescence spectra are used to identify the nature of different peaks. By combining experimental results and an energy-level structure analysis,origins of the multi-peaks are identified. Furthermore,inter-subband spacing of electrons and holes are deduced.展开更多
In this study,a facile alcoholysis method was developed to synthesize BiOCI_(x)Br_(1_x)nanoplates at room temperature and atmospheric pressure.In this route,strong acid or alkaline environment was absolutely avoided t...In this study,a facile alcoholysis method was developed to synthesize BiOCI_(x)Br_(1_x)nanoplates at room temperature and atmospheric pressure.In this route,strong acid or alkaline environment was absolutely avoided to realize the high exposure of{001}crystal facets.The regular changes in XRD peaks and cell parameters as a function of the Br content strongly declared that the obtained BiOCIxBrl_x products belonged to a group of solid solutions.The 2D nanosheets with in-plane wrinkles were clearly observed in TEM images.Interestingly,as the Br content increased,band gaps of BiOCI_(x)Br_(1_x)solid solutions gradually decreased.The photocatalytic degradation of RhB under simulated sunlight irradiation indicated that BiOCI0.sBr0.5 had the best photocatalytic activity.From the viewpoint of crystal chemistry,the photocatalytic activity of BiOCI_(x)Br_(1_x)solid solutions was closely related with the exposure amount of{001}facets,interlayer spacing of(001)plane and energy-level position of valence band.展开更多
Undoped LaAlO3 and 1 at.%Ce:LaAlO3 single crystals were grown by the Czochralski process.Absorption and fluorescence spectra were measured at room temperature.Detailed energy levels structure of Ce:LaAlO3 was determin...Undoped LaAlO3 and 1 at.%Ce:LaAlO3 single crystals were grown by the Czochralski process.Absorption and fluorescence spectra were measured at room temperature.Detailed energy levels structure of Ce:LaAlO3 was determined.In this paper,two viewpoints were provided.The first one is:the energy levels structure of Ce:LaAlO3 is very similar to that of Ce:Lu2(SiO4)O which is a well-known scintillator.In the energy levels structure of Ce:LaAlO3 and Ce:Lu2(SiO4)O,the lowest 5d energy level of Ce 3+ is located below the bottom of the conduction band of host crystal and the other higher 5d energy levels of Ce 3+ are located above the bottom of the conduction band of host crystal.The second one is:Ce:LaAlO3 single crystal may not be suitable for scintillation application;by comparing the energy levels structures of Ce:LaAlO3 and Ce:Lu2(SiO4)O,the large energy difference(1.13 eV)between the two lowest 5d energy levels of Ce 3+ in LaAlO3 is a crucial factor that causes the luminescence quenching.展开更多
基金supported by the National Natural Science Foundation of China(22202102,62474194,22425903,U24A20568)the National Key R&D Program of China(2023YFB4204500)the Jiangsu Provincial Departments of Science and Technology(BE2022023,BK20220010,and BZ2023060)。
文摘Metal halide perovskites,owing to their remarkable optoelectronic properties and broad application prospects,have emerged as a research hotspot in materials science and photovoltaics.In addressing challenges related to energy loss,photoelectric conversion efficiency,and operational stability in perovskite solar cells(PSCs),various strategies have been proposed,such as improving perovskite crystallization,developing tandem architectures,and advancing interfacial engineering.However,the specific impact of these approaches on internal energy transfer and conversion mechanisms within PSCs remains insufficiently understood.This review systematically examines the relationship between energy and perovskite materials throughout the photon absorption to charge carrier transport process,with particular focus on key strategies for minimizing energy losses and their underlying influence on energy-level alignment-especially in the electron transport layer and hole transport layer.It summarizes optimal absorption conditions and contributing factors during energy transfer,alongside representative case studies of high-performing systems.By elucidating these mechanisms,this work offers valuable theoretical insights for optimizing energy-level alignment,reducing energy dissipation,and guiding experimental design in PSCs research.
文摘In this paper, we find the invariant eigen-operators （IEOs） and the energy-level gap of a system with a two-level atom interacting with single mode cavity field through multi-photon transition in the presence of a Kerr-like medium. From this work, one can see that the IEO method in many eases is simpler and easier on obtaining the energy-level gap formula than the usual way.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10174024 and 10474025)
文摘We investigate the energy-level shift of a hydrogen atom in a two-dimensional optical microcavity, where there exists a Bose-Einstein condensation of photons. It is found that below the critical temperature Tc, the energy-level shift of the bound electron is dependent on temperature, and it is a monotonically increasing function of the absolute temperature T. Especially, at the absolute zero temperature, the energy-level shift entirely comes from the Lamb shift, and the atom can be treated approximately, that is, in vacuum.
基金the National Natural Science Foundation of China.62171428Key Research Program of Frontier Sciences of CAS.QYZDY-SSW-JSC003。
文摘We propose aΛ-type superconducting three-energy-level device-based communication system for extremely weak microwave communication scenarios,for example,long-distance deep-space communication.We provide a system diagram and propose the frame synchronization and power estimation approaches based on pre-defined synchronization sequences.Based on the microwave response characteristics of the superconducting three-energy-level system,we further investigate the optimization of synchronization sequence and information symbol modulation.We show that three-energy-level systems with weak Markovianity can be approximated using independent identical distribution methods to obtain optimal synchronization sequences,and the optimal modulation is asymmetric.The proposed system design and optimization approaches are evaluated by numerical results.Moreover,we investigate the performance of the three-energy-level communication system in the presence of interference.Simulation results show that the three-energy-level communication system can tolerate more than 10 dB interference compared to long term evolution(LTE)systems and achieve the same communication rate for the same bandwidth and temperature.
基金Supported by National Natural Science Foundation of China (10505002, 10435010, 10605001, 10221003)Postdoctoral Science Foundation of China (20060390371)
文摘Different definitions for chiral doublet bands based on excitation energies, B(E2) and B(M1) respectively are discussed in the triaxial particle rotor model. For the ideal chiral geometry, the selection rules of the electromagnetic transitions in different band definitions are illustrated. It is also shown that the energy-level crossings between chiral doublet bands may occur.
基金supported by the National Basic Re-search Program of China(No.2010CB327601)the Na-tional Natural Science Foundation of China(No.61020106007,61108048)+1 种基金International Science&Technology Cooperation Program of China(No.2011DFR11010)the 111 Project(No.B07005).
文摘Some important insights into the electron-states-architecture (ESA) and its dimensionality (from 3 to 0) in a semiconductor (or generally crystalline) material are obtained. The self-consistency of the set of density of states (DOS) expressions with different dimensionalities is remediated through the clarification and rearrangement of the wave-function boundary conditions for working out the eigenvalues in the wave vector space. The actually too roughly observed and theoretically unpredicted critical points for the dimensionality transitions referring to the integer ones are revealed upon an unusual assumption of the intrinsic energy-level dispersion (ELD). The ELD based quantitative physical model had been established on an immediate instinct at the very beginning and has been properly modified afterwards. The uncertainty regarding the relationship between the de Broglie wavelength of electrons and the dimensionality transitions, seeming somewhat mysterious before, is consequentially eliminated. The effect of the material dimensions on the ELD width is also predicted and has been included in the model. The continuous evolution of the ESA dimensionality is convincingly and comprehensively interpreted and thus the area of the fractional ESA dimensionalities is opened. Another new assumption of the spatial extension shrinkage (SES) closely related to the ELD has also been made and thus the understanding of the behavior of an electron or, in a general sense, a particle has become more comprehensive. This work would manifest itself a new basis for further development of nanoheterostructures (or low dimensional heterostructures including the quantum wells, quantum wires, quantum dots and especially the hetero-dimensional structures). Expected should also be the possible inventions of some novel electronic and optoelectronic devices. More basically, it leads to a new quantum mechanical picture, the essential modifications of Schrödinger equation and Newtonian equation that give rise to a full cosmic-scope picture, and a super-low-speed relativity assumption.
基金Supported by the Key Project of the Ministry of Education of China under Grant No 306020, the National Natural Science Foundation of China, the National High-Tech ICF Committee in China and the Yin-He Super-computer Center, Institute of Applied Physics and Mathematics, Beijing, China, and the National Basic Research Programme of China under Grant No 2006CB921408.
文摘Using the multi-configuration Dirac-Fock self-consistent field method and the relativistic configuration interaction method with quantum-electrodynamics corrections performed by the GRASP code, we calculate the fine-structure energy levels of the ground-state configuration （1s^22s^22p^3） of the nitrogen isoelectronic sequence, according to the L-S coupling scheme with atomic number Z up to 22. Based on the calculated results, we elucidate the mechanism of the orderings of fine-structure energy levels of 2^ D3/2,5/2 and 2^P1/2,3/2 respectively, i.e. for 2^D3/2,5/2 orderings, the competition between the spin-orbit interactions and the Breit interactions; for 2^P1/2,3/2 orderings, the electron correlations, especially the electron correlations owing to the 2p^5 configuration interactions.
基金Natural Science Foundation of Inner Mongolia(Nos.2020BS01001 and 2022MS01014)the Basic Scientific Research Business Projects in Colleges and Universities Directly under Inner Mongolia Autonomous Region(No.GXKY22059)the Doctoral Scientific Research Foundation of Inner Mongolia Minzu University.(Nos.BS511 and BS625)。
文摘Nanorod is a unique low-dimensional nanometer structure in which the Landau level arrangement of polaron is essential for understanding its quasiparticle system.However,the stability of the polaron level is susceptible to external factors,such as changing magnetic fields.In this manuscript,the Pekar variational method is employed to calculate the external magnetic field's effect on the nanorod's polaron Landau level.It was found that different magnetic fields have different effects on the polaron energy levels of the nanorod,which demonstrated that the external environment had critical effects on the polaron energy levels.This study provides a theoretical basis for regulating the interaction between electrons and phonons in low-dimensional nanomaterials.
基金Supported by Foundation of President of Chinese Academy of Science
文摘By using Gumming （JC） model. energy-level gap of this the pseudo invariant eigen-operator method we The pseudo-invariant eigen-operator is found in JC Hamiltonian is derived. This approach seems analyze the field-intensity-dependent Jaynes terms of the supersymmetric generators. The concise.
基金the State Key Development Program for Basic Research of China(No.2006CB604904)the National Natural Science Foundation of China(Nos.60776037,60676029)~~
文摘Multi-peak structures in photoluminescence spectra of InAs/GaAs quantum dots are investigated. Excitation power-dependent photoluminescence spectra are used to identify the nature of different peaks. By combining experimental results and an energy-level structure analysis,origins of the multi-peaks are identified. Furthermore,inter-subband spacing of electrons and holes are deduced.
文摘In this study,a facile alcoholysis method was developed to synthesize BiOCI_(x)Br_(1_x)nanoplates at room temperature and atmospheric pressure.In this route,strong acid or alkaline environment was absolutely avoided to realize the high exposure of{001}crystal facets.The regular changes in XRD peaks and cell parameters as a function of the Br content strongly declared that the obtained BiOCIxBrl_x products belonged to a group of solid solutions.The 2D nanosheets with in-plane wrinkles were clearly observed in TEM images.Interestingly,as the Br content increased,band gaps of BiOCI_(x)Br_(1_x)solid solutions gradually decreased.The photocatalytic degradation of RhB under simulated sunlight irradiation indicated that BiOCI0.sBr0.5 had the best photocatalytic activity.From the viewpoint of crystal chemistry,the photocatalytic activity of BiOCI_(x)Br_(1_x)solid solutions was closely related with the exposure amount of{001}facets,interlayer spacing of(001)plane and energy-level position of valence band.
文摘Undoped LaAlO3 and 1 at.%Ce:LaAlO3 single crystals were grown by the Czochralski process.Absorption and fluorescence spectra were measured at room temperature.Detailed energy levels structure of Ce:LaAlO3 was determined.In this paper,two viewpoints were provided.The first one is:the energy levels structure of Ce:LaAlO3 is very similar to that of Ce:Lu2(SiO4)O which is a well-known scintillator.In the energy levels structure of Ce:LaAlO3 and Ce:Lu2(SiO4)O,the lowest 5d energy level of Ce 3+ is located below the bottom of the conduction band of host crystal and the other higher 5d energy levels of Ce 3+ are located above the bottom of the conduction band of host crystal.The second one is:Ce:LaAlO3 single crystal may not be suitable for scintillation application;by comparing the energy levels structures of Ce:LaAlO3 and Ce:Lu2(SiO4)O,the large energy difference(1.13 eV)between the two lowest 5d energy levels of Ce 3+ in LaAlO3 is a crucial factor that causes the luminescence quenching.
