Enhancing atomic layer deposition—microchannel plate gain with Cs activation in photoelectric devices

Gain is a key performance indicator of microchannel plates (MCPs). By depositing metal oxides with high secondary electron emission coefficients within the channels of MCPs using atomic layer deposition technology, the gain of MCPs in devices can be significantly increased. However, metal oxides generally have higher work functions, which inhibit the escape of electrons and limit the extent of gain enhancement in MCPs. Cesium is a commonly used material in the fabrication of photocathodes for vacuum photoelectric devices, typically employed to reduce the surface work function of photocathodes and increase the emission ratio of photoelectrons, thereby enhancing the sensitivity of the photocathodes. Introducing Cs atoms into the surface of the metal oxide film deposited inside the MCP channels during the fabrication of photoelectric devices can similarly reduce the work function of the metal oxide film, leading to an increase in MCP gain of over three times. This method successfully achieved the simultaneous improvement of both the photocathode and the MCP performance using the same activation source.