The quantum efficiency of Cu is found to increase dramatically when coated by a CsI film and then irradiated by a UV laser. Over three orders of magnitude quantum efficiency enhancement at 266 nm is observed in CsI/Cu(100), indicating potential application in future photocathode devices. Upon laser irradiation, a large work function reduction to a value less than 2 eV is also observed, significantly greater than for similarly treated CsBr/Cu(100). The initial QE enhancement, prior to laser irradiation, is attributed to interface interaction, surface cleanliness and the intrinsic properties of the Cs halide film. Further QE enhancement following activation is attributed to formation of inter-band states and Cs metal accumulation at the interface induced by laser irradiation.
Revised: August 9, 2018 |
Published: April 28, 2014
Citation
Kong L., A.G. Joly, T.C. Droubay, Y. Gong, and W.P. Hess. 2014.Enhanced Quantum Efficiency From Hybrid Cesium Halide/Copper Photocathode.Applied Physics Letters 104, no. 17:Article No. 171106.PNNL-SA-101664.doi:10.1063/1.4874339