Alkali azide based growth of high quantum efficiency photocathodes

The authors report on successful growth of bialkali photocathode based on CsK2Sb using the alkali metal vapors generated by thermal decomposition of alkali azides. Details about the ultrahigh vacuum growth system and the procedure used are provided. The final quantum efficiency of the photocathode under illumination with 532nm laser is 9.6%. This value is comparable to the largest ones obtained in our previous experiments using commercial dispensers, indicating that alkali azides are a viable alternative. (C) 2014 American Vacuum Society.