We are excited to share our newest paper where we selectively examine an asymmetric potential in the buried layer of solar cell devices by means of nonlinear X-ray spectroscopy. This collaborative work under lead of Walter Drisdell (LBNL) was published in Applied Physics Letters.

In this work, we systematically investigate Al/LiF/SiO2/Si, TiO2/SiO2/Si, and Al2O3/SiO2/Si multilayer structures by probing around the Si L edge using second-harmonic XUV spectroscopy. We directly observe existence of the band bending effect in the SiO2 nanolayer, buried in the heterostructures. The results demonstrate high sensitivity of the method to the asymmetric potential that determines performance of functional materials for photovoltaics or other optoelectronic devices.

This work was done in collaboration with researchers from the University of Tokyo, the University of Melbourne, UC Berkeley/LBNL, and the University of Nevada Las Vegas. The measurements were conducted at the SACLA free-electron laser at RIKEN in Japan.

Open-access to the research paper at Applied Physics Letters:
https://pubs.aip.org/aip/apl/article/123/3/031602/2902887/Detecting-driving-potentials-at-the-buried-SiO2