Au-Coated Mcp Photo-Detector and Its Energy Spectrum Response

Micro-channel Plate (MCP), which can be served as electron multiplier achieved by the surface of micro-pores that has some electrical conductivity and performs well in producing secondary electrons, is a fiberglass plate made of silicate glass containing oxide of lead, bismuth and otherwise. Once coated with cathode film both sides, MCP is capable of responding to ultraviolet (UV) of several eV and x-ray of several keV. When gold is applied as photocathode, it has good stability of emission, photoelectric emission character would not be changed even though exposed in the air several times, and the photoelectric current density distributes uniformly. This article introduces a special photo-detector, which employs MCP as dielectric substrate, and evaporates a layer of thin Au on the front surface acted as the photocathode and input electrode, while a layer of general electrode on the back surface. In addition, an electron receiver is also needed to structure the photo-detector. Energy spectrum response at ultraviolet band of this Au coated MCP photo-detector was measured through measuring the response current of the detector between 200 similar to 340 nm (3.66 similar to 6.22 eV) directly. The selective photoemission of Au has been found, which had been found only for alkali metals.