A study on the optics of copper indium gallium (di)selenide (CIGS) solar cells with ultra-thin absorber layers

We present a systematic study of the effect of variation of the zinc oxide (ZnO) and copper indium gallium (di)selenide (CIGS) layer thickness on the absorption characteristics of CIGS solar cells using a simulation program based on finite element method (FEM). We show that the absorption in the CIGS layer does not decrease monotonically with...

Chemical interaction of B4C, B, and C with Mo/Si layered structures

To enhance the thermal stability, B4C diffusion barrier layers are often added to Mo/Si multilayer structures for extreme ultraviolet optics. Knowledge about the chemical interaction between B4C and Mo or Si, however is largely lacking. Therefore, the chemical processes during annealing up to 600?°C of a Mo/B4C/Si layered structure have been...

Nanomechanical properties of few-layer graphene membranes

We have measured the mechanical properties of few-layer graphene and graphite flakes that are suspended over circular holes. The spatial profile of the flake’s spring constant is measured with an atomic force microscope. The bending rigidity of and the tension in the membranes are extracted by fitting a continuum model to the data. For flakes...

Stress in tungsten carbide-diamond like carbon multilayer coatings

Tungsten carbide-diamond like carbon (WC-DLC) multilayer coatings have been prepared by sputter deposition from a tungsten-carbide target and periodic switching on and off of the reactive acetylene gas flow. The stress in the resulting WC-DLC multilayers has been studied by substrate curvature. Periodicity and microstructure have been studied by...

Determination of in-depth density profiles of multilayer structures

We developed and demonstrate an analysis method in which we calibrate the intensity scale of cross-sectional transmission electron microscopy (TEM) using Cu K? reflectometry. This results in quantitative in-depth density profiles of multilayer structures. Only three free parameters are needed to obtain the calibrated profiles, corresponding to...