Different charging behaviors between electrons and holes in Si nanocrystals embedded in SiN_x matrix by the influence of near-interface oxide traps

Si-rich silicon nitride films are prepared by plasma-enhanced chemical vapor deposition method, followed by thermal annealing to form the Si nanocrystals（Si-NCs） embedded in Si Nx floating gate MOS structures. The capacitance–voltage（C–V）, current–voltage（I–V）, and admittance–voltage（G–V） measurements are used to investigate the charging characteristics. It is found that the maximum flat band voltage shift（△VFB） due to full charged holes（～ 6.2 V） is much larger than that due to full charged electrons（～ 1 V）. The charging displacement current peaks of electrons and holes can be also observed by the I–V measurements, respectively. From the G–V measurements we find that the hole injection is influenced by the oxide hole traps which are located near the Si O2/Si-substrate interface. Combining the results of C–V and G–V measurements, we find that the hole charging of the Si-NCs occurs via a two-step tunneling mechanism. The evolution of G–V peak originated from oxide traps exhibits the process of hole injection into these defects and transferring to the Si-NCs.

Progress in hole-transporting materials for perovskite solar cells

In recent years the photovoltaic community has witnessed the unprecedented development of perovskite solar cells（PSCs） as they have taken the lead in emergent photovoltaic technologies. The power conversion efficiency of this new class of solar cells has been increased to a point where they are beginning to compete with more established technologies. Although PSCs have evolved a variety of structures, the use of hole-transporting materials（HTMs） remains indispensable. Here, an overview of the various types of available HTMs is presented. This includes organic and inorganic HTMs and is presented alongside recent progress in associated aspects of PSCs, including device architectures and fabrication techniques to produce high-quality perovskite films. The structure, electrochemistry, and physical properties of a variety of HTMs are discussed, highlighting considerations for those designing new HTMs. Finally, an outlook is presented to provide more concrete direction for the development and optimization of HTMs for highefficiency PSCs.

Charged Fermions Tunneling from a Rotating Charged Black Hole in 5-Dimensional Gauged Supergravity

Recent research shows that Hawking radiation from black hole horizon can be treated as a quantum tunneling process, and fermions tunneling method can successfully recover Hawking temperature. In this tunneling framework, choosing a set of appropriate matrices γ^μ is an important technique for fermions tunneling method. In this paper, motivated by Kerner and Man＇s fermions tunneling method of 4 dimension black holes, we further improve the analysis to investigate Hawking tunneling radiation from a rotating charged black hole in 5-dimensional gauged supergravity by constructing a set of appropriate matrices γ^μ for general covariant Dirac equation. Finally, the expected Hawking temperature of the black hole is correctly recovered, which takes the same form as that obtained by other methods. This method is universal, and can also be directly extend to the other different-type 5-dimensional charged black holes.

Abbott-Deser-Tekin Charge of Dilaton Black Holes with Squashed Horizons

We consider the conserved charge of static black holes with squashed horizons in the Einstein-Maxwell-dilaton theory via both the Abbott-Deser-Tekin （ADT） method and its off-shell generalization. We first make use of the original ADT method to compute the mass of the dilaton squashed black holes in terms of three different reference spacetimes, which are the asymptotic geometry, the flat background and the spacetime of the Kaluza- Klein monopole with boundary matched to the original metric, respectively. Each mass satisfies the first law of black hole thermodynamics, although the mass computed on the basis of the boundary matching the Kaluza- Klein monopole is different from that of the other two reference spacetimes. Then the mass of the black holes is evaluated through the off-shell generalized ADT method.

Holographic heat engine efficiency of hyperbolic charged black holes

We consider a four-dimensional charged hyperbolic black hole as working matter to establish a black hole holographic heat engine,and use the rectangular cycle to obtain the heat engine efficiency.We find that when the increasing of entropy is zero,the heat engine efficiency of the hyperbolic black hole becomes the well-known Carnot efficiency.We also find that less charge corresponds to higher efficiency in the case of˜q>0.Furthermore,we study the efficiency of the flat case and spherical case and compare the efficiency with that of the hyperbolic charged black holes.Finally,we use numerical simulation to study the efficiency in benchmark scheme.

Joule-Thomson Expansion of d-Dimensional Charged Anti-de Sitter Black Holes Surrounded by Quintessence with a Cloud of Strings Background

Effects of the dimension on the Joule-Thomson expansion are investigated in details by considering the case of d-dimensional(d≥5)charged anti-de Sitter(AdS)black hole which is surrounded by the quintessence with a cloud of strings background.Firstly,the thermodynamic quantity of this black hole is reviewed.Secondly,three important features of the Joule-Thomson expansion in different dimensions are discussed,including the Joule-Thomson coefficients,inversion curves,and isenthalpic curves.Finally,the effects of the charge,the quintessence and strings cloud parameters on the Joule-Thomson expansion in the case of six-dimensional black hole are studied.

Thermal properties of regular black hole with electric charge in Einstein gravity coupled to nonlinear electrodynamics

We propose a regular spherically symmetric spacetime solution with three parameters in Einstein gravity coupled to nonlinear electrodynamics(NED), which describes the NED black hole with electric charge. It is found that the system enclosed by the horizon of NED spacetime satisfies the first law of thermodynamics. In order to obtain the NED spacetime with only electric charge, the case of two parameters taking the same value is considered. In this case, we express the mass of the NED spacetime as a function of the entropy and electric charge of the NED black hole, give the Smarr-like formula and the approximate Smarr formula for the mass of NED spacetime.

Accretion onto the Magnetically Charged Regular Black Hole

We investigate the accretion process for static spherically symmetric geometry, i.e., magnetically charged regular black hole with isotropic fluid. W＇e obtain generalized expressions for the velocity （u（r））, speed of sound （cs2）, energy density （ρ（r） ） and accretion rate （M） at the critical point near the regular black hole during the accretion process. We also plot these physical parameters against fixed values of charge, mass and different values of equation of state parameter to study the process of accretion. We find that radial velocity and energy density of the fluid remain positive and negative as well as rate of change of mass is increased and decreased for dust, stiff, quintessence fluid and phantom-like fluid, respectively.

Electronic Structure and Catalysis on (001) Polar Surface of Cubic Zirconia

The electronic structure of （001） polar surface of cubic zirconia was studied by GGA（WC） approximation. We found the cubic lattice near （001） surface showed an intensive tendency to transfer to tetragonal lattice. The metallic state appeared on both the terminations. For O-termination, some O2p states were vacated and hole carriers concentrated on surface oxygen-ions. For Zr-termination, some Zr4d states became partial occupied for the loss of O2p states. We observed the hole states were mainly localized at the corresponding ions on surface for both the terminations, while the charge states on Zr-termination were dispersed on surface.

Refined symmetry-resolved Page curve and charged black holes

The Page curve plotted using the typical random state approximation is not applicable to a system with conserved quantities,such as the evaporation process of a charged black hole,during which the electric charge does not macroscopically radiate out with a uniform rate.In this context,the symmetry-resolved entanglement entropy may play a significant role in describing the entanglement structure of such a system.We attempt to impose constraints on microscopic quantum states to match the macroscopic phenomenon of charge radiation during black hole evaporation.Specifically,we consider a simple qubit system with conserved spin/charge serving as a toy model for the evaporation of charged black holes.We propose refined rules for selecting a random state with conserved quantities to simulate the distribution of charges during the different stages of evaporation and obtain refined Page curves that exhibit distinct features in contrast to the original Page curve.We find that the refined Page curve may have a different Page time and exhibit asymmetric behavior on both sides of the Page time.Such refined Page curves may provide a more realistic description for the entanglement between the charged black hole and radiation during the evaporation process.

Thermodynamics of charged black holes in Maxwell-dilaton-massive gravity

Considering the nonminimal coupling of the dilaton field to the massive graviton field in Maxwelldilaton-massive gravity,we obtain a class of analytical solutions of charged black holes,which are neither asymptotically flat nor(A)dS.The calculated thermodynamic quantities,such as mass,temperature,and entropy,verify the validity of the first law of black hole thermodynamics.Moreover,we further investigate the critical behaviors of these black holes in the grand canonical and canonical ensembles and find a novel critical phenomenon never before observed,known as the"reverse"reentrant phase transition with a tricritical point.It implies that the system undergoes a novel"SBH-LBH-SBH"phase transition process and is the reverse of the"LBH-SBH-LBH"process observed in reentrant phase transitions.

Evolution of light deflection and shadow from a gauge-potential-like AdS black hole under the influence of a non-magnetic plasma medium

We investigate the light deflection in the weak field approximation from the accelerating charged AdS black hole.For this purpose,we apply the Gauss–Bonnet theorem to calculate the light deflection in the weak field area and use the Gibbons–Werner approach to analyze the optical geometry of the accelerating charged AdS black hole in the non-magnetic plasma absence/presence of a non-magnetic medium.We also represent the graphical behavior of the light deflection angle w.r.t.the impact parameter.We also compute the light deflection angle using Keeton and Petters approximations under the impact of accelerating charged AdS black hole geometry.Furthermore,by using the ray-tracing approach,we determine the shadow in the nonmagnetic plasma presence and also demonstrate that graphical shadow has an impact on the gauge potential,non-magnetic plasma frequencies and charge.

Charged fermions tunneling radiation from the charged Gdel black hole in minimal five-dimensional gauged supergravity

In this paper,we extend fermions tunneling radiation to the case of five-dimensional charged black holes by introducing a set of appropriate matrices γμ for general covariant Dirac equation of 1/2 spin charged Dirac particles in the electromagnetic field.It is expected that our result can strengthen the validity and power of the tunneling method.We take the charged Gdel black holes in minimal five-dimensional gauged supergravity for example in order to present a reasonable extension of the tunneling method.As a result,we get fermions tunneling probability of the black hole and the Hawking temperature near the event horizon.

Charged torus-like black holes as heat engines

We investigate the thermodynamical properties of charged torus-like black holes and take it as the working substance to study the heat engines.In the extended phase space,by interpreting the cosmological constant as the thermodynamic pressure,we derive the thermodynamical quantities by the first law of black hole thermodynamics and obtain the equation of state.Then,we calculate the efficiency of the heat engine in the Carnot cycle as well as the rectangular cycle,and investigate how the efficiency changes with respect to volume.In addition,to avoid a negative temperature,we emphasize that the charge of this black hole cannot be arbitrary.Last,we check the calculation accuracy of a benchmark scheme and discuss the upper bound and lower bound for charged torus-like black hole in the scheme.

Joule-Thomson expansion of charged dilatonic black holes

Based on the Einstein-Maxwell theory,the Joule-Thomson(J-T)expansion of charged dilatonic black holes(the solutions are neither flat nor AdS)in(n+1)-dimensional spacetime is studied herein.To this end,we analyze the effects of the dimension n and dilaton fieldαon J-T expansion.An explicit expression for the J-T coefficient is derived,and consequently,a negative heat capacity is found to lead to a cooling process.In contrast to its effect on the dimension,the inversion curve decreases with charge Q at low pressures,whereas the opposite effect is observed at high pressures.We can observe that with an increase in the dimension n or parameter a,both the pressure cut-off point and the minimum inversion temperature T_(min)change.Moreover,we analyze the ratio T_(min)/T_(c)numerically and discover that the ratio is independent of charge;however,it depends on the dilaton field and dimension:for n=3 andα=0,the ratio is 1/2.The dilaton field is found to enhance the ratio.In addition,we identify the cooling-heating regions by investigating the inversion and isenthalpic curves,and the behavior of the minimum inversion mass M_(min)indicates that this cooling-heating transition may not occur under certain special conditions.

Shadows of magnetically charged rotating black holes surrounded by quintessence

In this work,we study the optical properties of a class of magnetically charged rotating black hole spacetimes.The black holes in question are assumed to be immersed in the quintessence field,and subsequently,the resulting black hole shadows are expected to be modified by the presence of dark energy.We investigate the photon region and the black hole shadow,especially their dependence on the relevant physical conditions,such as the quintessence state parameter,angular momentum,and magnetic charge magnitude.The photon regions depend sensitively on the horizon structure and possess intricate features.Moreover,from the viewpoint of a static observer,we explore a few observables,especially those associated with the distortion of the observed black hole shadows.

Dynamic phase transition of charged dilaton black holes

The dynamic phase transition of charged dilaton black holes is investigated in this paper.The Gibbs free energy landscape is introduced,and the corresponding G_(L) is calculated for the dilaton black hole.We numerically solve the Fokker-Planck equation constrained by only the reflecting boundary condition.The effects of dilaton gravity on the probabilistic evolution of dilaton black holes are explored.Firstly,the horizon radius difference between a large dilaton black hole and a small dilaton black hole increases with the parameterα.Secondly,with increasingα,the system needs much more time to achieve a stationary distribution.Finally,the values attained forρ(rl,t)andρ(rs,t)vary withα.Additionally,by resolving the Fokker-Planck equation constrained by both the reflecting boundary condition and absorbing boundary condition,we investigate the first passage process of dilaton black holes.The initial peak decays more slowly with increasingα,which can also be observed via the slowing decay ofΣ(t)(the sum of the probability of the black hole system not having completed a first passage by time t).Moreover,the time corresponding to the single peak of the first passage time distribution is found to increase with the parameterα.Considering these observations,the dilaton field is found to slow down the dynamic phase transition process between a large black hole and a small black hole.