Per Erik Vullum
Per Erik Vullum
Publikasjoner og ansvarsområder
Influence of surface topography, defects and their nature on the contact formation in thick film Ag metallization
TEM characterization of pure and transition metal enhanced NaAlH4
Possibilities and limitations in using transmission electron microscopy to characterize pure NaAlH4 and transition metal enhanced NaAlH4 have been investigated in detail. NaAlH4 is extremely sensitive to O-2 and H2O and must be handled under inert atmosphere at all times. Furthermore, it is highly u...
Cryomilling as a route to nanostructured materials for thermoelectric - the case of ZnSb
Positioning effects on quantum dot solar cells grown by molecular beam epitaxy
We report current-voltage and spectral response characteristics of high density InAs/GaAs quantum dot (QD) solar cells with different positions where dots are located. The short circuit current density (J(sc)), open circuit voltage (V-oc), and external quantum efficiency of these cells under air mas...
TEM analysis of catalyst and energy storage materials
Transmission electron microscopy (TEM) is an essential tool in the study of catalyst and hydrogen storage materials. Two fundamental obstacles are the reactivity with the atmosphere, which make sample handling and transfer procedures essential, and the stability of the sample under the electron beam...
Solid state hydrogen storage and interfaces in PV solar cells: Different meeting points between modelling and experiments
Modelling of interfaces for high performance solar cell materials
The resistance at the metal contact-semiconductor interface and recombination at the passivating layer-semiconductor interface are two important bottlenecks for improving the performance of current solar cells. These processes are quantum mechanical by nature, but so far most studies and attempts to...
ZnO Nanostructures Grown by Pulsed Laser Deposition
Observations of nanoscopic, face centered cubic Ti and TiHx
Transmission electron microscopy has been used to study ball milled and H cycled NaAlH4 with 10 mol% TiCl3. Isolated from the main phases in this hydrogen storage system, nanocrystalline aggregates of fcc TiH (x) (0a parts per thousand currency signx < 0.67) were found. The value of x was determi...