A strain-isolation design for stretchable electronics

Stretchable electronics represents a direction of recent development in next-generation semiconductor devices.Such systems have the potential to offer the performance of conventional wafer-based technologies,but they can be stretched like a rubber band,twisted like a rope, bent over a pencil,and folded like a piece of paper.Isolating the active devices from strains associated with such deformations is an important aspect of design.One strategy involves the shielding of the electronics from deformation of the substrate through insertion of a compliant adhesive layer. This paper establishes a simple,analytical model and validates the results by the finite element method.The results show that a relatively thick,compliant adhesive is effective to reduce the strain in the electronics,as is a relatively short film.

Effect of spatially nonlocal versus local optical response of a gold nanorod on modification of the spontaneous emission

The spontaneous emission rate of a two-level quantum emitter(QE)near a gold nanorod is numerically investigated.Three different optical response models for the free-electron gas are adopted,including the classical Drude local response approximation,the nonlocal hydrodynamic model,and the generalized nonlocal optical response model.Nonlocal optical response leads to a blueshift and a reduction in the enhancement of the spontaneous emission rate.Within all the three models,the resonance frequency is largely determined by the aspect ratio(the ratio of the nanorod length to the radius)and increases sharply with decreasing aspect ratio.For nanorod with a fixed length,it is found that the larger the radius is,the higher the resonance frequency is,and the smaller the enhancement is.However,if the length of the nanorod increases,the peak frequency falls sharply,while the spontaneous emission enhancement grows rapidly.For nanorod with a fixed aspect ratio,the peak frequency decreases slowly with increasing nanorod size.Larger nanorod shows smaller nonlocal effect.At a certain frequency,there is an optimal size to maximize the enhancement of the spontaneous emission rate.Higher order modes are more affected by the nonlocal smearing of the induced charges,leading to larger blueshift and greater reduction in the enhancement.These results should be significant for investigating the spontaneous emission rate of a QE around a gold nanorod.

High-rate performance and super long-cycle stability of Na_(3)V_(2)(PO_(4))_(3)cathode material coated by diatomic doped carbon

Na_(3)V_(2)(PO_(4))_(3)is considered as one of the most promising cathodes for sodium ion batteries due to its excellent thermal stability,long cycle life and high energy density.However,the inferior intrinsic electronic conductivity which brings about the poor rate capability and cycling performance hinders its commercial application.Herein,the S-N co-doped carbon-coated Na_(3)V_(2)(PO_(4))_(3)(NVP@SNC)has been synthesized to resolve the problem.The prepared NVP@SNC forms a hierarchical structure assembled with nanosheets,which is in favor of the electrolyte infiltration and shortening the Na^(+)transmission distance.Numerous lattice defects can be induced in carbon layer by the co-doped elements(S-N),which reduce the Na^(+)diffusion energy barriers and provide adequate Na^(+)migration channels,thus jointly boosting the Na^(+)diffusion coefficient.Consequently,the NVP@SNC cathode shows a high reversible capacity with outstanding rate performance and super long-cycle stability.When discharged at 2.0C,it delivers the capacity near to the theoretical value with a capacity retention of 88.7%after 400cycles.Even if the current is as high as 50.0C,a high capacity of 58.6 mAh·g^(-1)has been released,and41.4 mAh·g^(-1)has been remained after the super long cycling of 4000 circles.This study is expected to supply a new thought of developing high-performance cathodes by diatomic doping for sodium ion battery.

Effectiveness of Non-Markovian Methods for Quantum Discord Dynamics of Non-coupled Two-Qubit System

The dissipative dynamics of non-coupled two qubits interacting with independent reservoir is studied by solving the non-Markovian master equation. In order to examine the effectiveness of the Nakajima-Zwanzig and timeconvolutionless master equations in the description of quantum correlation dynamics, different coupled regimes are investigated. The comparison between the above two master equation methods for investigating the dynamics of quantum discord is also made. Finally, we further confirm that the two master equations should be applied in different regimes of qubits coupled to their reservoirs, respectively.