Enhanced Quantum Efficiency of Photocathodes with Polarized Emission

Photocathodes with spin-polarized electron emission are used in physics research. Current photocathodes offer high polarization, but low total currents, and have limited lifetime. Research involving these polarized electrons would be more productive if a higher electron current were provided. This program seeks to increase the delivered polarized electron current from the photocathodes by adding integrated light reflectors to the device structure. These reflectors could concentrate more light energy to the creation of electron current, rather than being wasted as heat in present designs. As a consequence, these photocathodes would also have longer lifetimes. In the Phase I approaches and materials were assayed to best reach the goal of a high current spin polarized photocathode. A prototype design for such a device was developed and deemed feasible for production in a Phase II. The Phase II will fabricate and characterize the device design postulated by the Phase I. As part of the fabrication process several tools will be applied to the growth process to ensure that the end product has the highest chances for success. Spin-polarized electrons have particular application in the field of experimental physics. A subset of this is research into subatomic particles and anti-matter. On a more accessible level such electrons are used in spin polarized low energy electron microscopy, which allows certain materials to be probed to reveal novel properties. At a grander scale polarized electrons also have application to quantum computing and data storage. Spin polarized photocathode, and spin polarized electron source.