Enhanced photoelectron emission in a large area aluminum nanohole array via a deep-UV surface plasmon

Abstract

We measured the photoelectron emission efficiency of aluminum (Al) nanohole arrays fabricated by colloidal lithography and demonstrated the enhancement of photoelectron emission in the deep-UV region via surface plasmon resonances. The Al nanohole arrays for increasing absorption in the deep-UV region were designed using the finite-difference time-domain method and used as photocathodes to enhance the photoelectron emission efficiency. The enhancement factor improved by up to 3.5 times for the optimized nanohole array. Using a two-dimensional mapping system, we demonstrated that the photoelectron emission depended on the uniformity of the sample and diameter of the nanohole arrays. Al nanohole arrays fabricated by colloidal lithography can be used to develop highly sensitive surface-detecting optical sensors and highly efficient surface-emitting electron sources. The two-dimensional mapping system can facilitate the development of highly efficient photocathodes.