@article{bibcite_8805, author = {D. Chaykina and I. Usman and G. Colombi and H. Schreuders and B. Tyburska-Pueschel and Z. Wu and S. W.H. Eijt and L. J. Bannenberg and G. A. de Wijs and B. Dam}, title = {Aliovalent Calcium Doping of Yttrium Oxyhydride Thin Films and Implications for Photochromism}, abstract = {To develop an understanding of the photochromic effect in rare-earth metal oxyhydride thin films (REH3{\textendash}2xOx, here RE = Y), we explore the aliovalent doping of the RE cation. We prepared Ca-doped yttrium oxyhydride thin films ((CazY1{\textendash}z)HxOy) by reactive magnetron cosputtering with Ca doping concentrations between 0 and 36 at. \%. All of the films are semiconductors with a constant optical band gap for Ca content below 15\%, while the band gap expands for compositions above 15\%. Ca doping affects the photochromic properties, resulting in (1) a lower photochromic contrast, likely due to a lower H{\textendash} concentration, and (2) a faster bleaching speed, caused by a higher pre-exponential factor. Overall, these results point to the importance of the H{\textendash} concentration for the formation of a {\textquotedblleft}darkened{\textquotedblright} phase and the local rearrangement of these H{\textendash} for the kinetics of the process. }, year = {2022}, journal = {Journal of Physical Chemistry C}, volume = {126}, pages = {14742{\textendash}14749}, month = {09/2022}, doi = {10.1021/acs.jpcc.2c04456}, language = {eng}, }