Switching mechanism for TiO_2 memristor and quantitative analysis of exponential model parameters

The memristor, as the fourth basic circuit element, has drawn worldwide attention since its physical implementation was released by HP Labs in 2008. However, at the nano-scale, there are many difficulties for memristor physical realization. So a better understanding and analysis of a good model will help us to study the characteristics of a memristor. In this paper, we analyze a possible mechanism for the switching behavior of a memristor with a Pt/TiO2/Pt structure, and explain the changes of electronic barrier at the interface of Pt/TiO2. Then, a quantitative analysis about each parameter in the exponential model of memristor is conducted based on the calculation results. The analysis results are validated by simulation results. The efforts made in this paper will provide researchers with theoretical guidance on choosing appropriate values for(α, β, χ, γ) in this exponential model.

Physical model for the exotic ultraviolet photo-conductivity of ZnO nanowire films

Employing a simple and efficient method of electro-chemical anodization, ZnO nanowire films are fabricated on Zn foil, and an ultraviolet （UV） sensor prototype is formed for investigating the electronic transport through back-to-back double junctions. The UV （365 nm） responses of surface-contacted ZnO film are provided by I-V measurement, along with the current evolution process by on/off of UV illumination. In this paper, the back-to-back metal-seconductor-metal （M-S-M） model is used to explain the electronic transport of a ZnO nanowire film based structure. A thermionic-field electron emission mechanism is employed to fit and explain the as-observed UV sensitive electronic transport properties of ZnO film with surface-modulation by oxygen and water molecular coverage.

Chemical adsorption on 2D dielectric nanosheets for matrix free nanocomposites with ultrahigh electrical energy storage

Relaxor ferroelectric polymers display great potential in capacitor dielectric applications because of their excellent flexibility,light weight,and high dielectric constant.However,their electrical energy storage capacity is limited by their high conduction losses and low dielectric strength,which primarily originates from the impact-ionization-induced electron multiplication,low mechanical modulus,and low thermal conductivity of the dielectric polymers.Here a matrix free strategy is developed to effectively suppress electron multiplication effects and to enhance mechanical modulus and thermal conductivity of a dielectric polymer,which involves the chemical adsorption of an electron barrier layer on boron nitride nanosheet surfaces by chemically adsorbing an amino-containing polymer.A dramatic decrease of leakage current(from 2.4×10^(-6)to 1.1×10^(-7)A cm^(-2)at 100 MV m^(-1))and a substantial increase of breakdown strength(from 340 to 742 MV m^(-1))were achieved in the nanocompostes,which result in a remarkable increase of discharge energy density(from 5.2 to 31.8 J cm^(-3)).Moreover,the dielectric strength of the nanocomposites suffering an electrical breakdown could be restored to 88%of the original value.This study demonstrates a rational design for fabricating dielectric polymer nanocomposites with greatly enhanced electric energy storage capacity.