Hot electron photoemission in metal–semiconductor structures aided by resonance tunneling

Abstract

Enhancement of the surface photoemission from metal into semiconductor by resonance tunneling of photoexcited electrons through (quasi-) discrete level in quantum well, located within Schottky barrier of the metal–semiconductor interface, is studied theoretically taking into account the difference between the electron masses in metal and semiconductor. It is shown, in particular, that resonance tunneling through the discrete level can lead to the redshift of the threshold wavelength of surface photoeffect, higher slope linear growth in photocurrent near the threshold (in contrast to quadratic growth, i.e., Fowler's law), and the possibility to increase substantially the photoemission efficiency similarly to recent experimental results on hot carrier generation in plasmonic structures with a discrete energy level at metal interface. The difference in the effective masses is shown to significantly affect the results. Double-barrier tunneling structures with resonant tunneling may become attractive for applications in photochemistry and in plasmonic photodetectors in near IR and middle IR regions of the spectrum.