Elastic property determination of nanostructured W/Cu multilayer films on a flexible substrate

An experimental method for a single layer is extended to determine the elastic properties of nanostructured W/C u multilayers on a flexible substrate.The strain difference between the W/Cu-polyimide-W/Cu composite and the uncoated substrate,measured by dual digital image correlation,allows us to extract the effective Young's modulus of W/Cu multilayers(20 periods)equaling 216±13 GPa.Finite element method is then performed,which agrees well with the experiment and classical rule of mixture(ROM)theory demonstrating that the extension to multilayers is effective and reliable.The numerical analysis also interestingly shows that the strain difference is linearly related to the thickness ratio(W/Cu),periods and sublayer thickness,respectively.In contrast to ROM theory,this approach could potentially be used for the evaluation of properties and design of emerging/unknown functional multilayers,whether or not they are crystalline or amorphous.

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quan- titatively estimate the interfacial energy of the nanostructured multilayer films （NMFs） adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be ~ 5.0 J/m2 for Cu/Cr, ~4.1 J/m2 for Cu/Ta, ~ 2.8 J/m2 for Cu/Mo, ~ 1.1 J/m2 for Cu/Nb, and ~ 1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.

Understanding the role of interface in advanced semiconductor nanostructure and its interplay with wave function overlap

As the proportion of interfaces increases rapidly in nanomaterials,properties and quality of interfaces hugely impact the performance of advanced semiconductors.Here,the effect of interfaces is explored by comparatively studying two InAs/AlSb superlattices with and without the thin InAsSb layers inserted inside each InAs layers.Through strain mapping,it indicates that the addition of interfaces leads to an increase of local strain both near interfaces and inside layers.Meantime,owing to the creation of hole potential wells within the original electron wells,the charge distribution undergoes an extra electron-hole alternating arrangement in the structure with inserted layers than the uninserted counterpart.Such a feature is verified to enhance electron-hole wave function overlap by theoretical simulations,which is a must for better optical performance.Furthermore,with an elaborate design of the inserted layers,the wave function overlap could be boosted without sacrificing other key device performances.