Light emission from the Au/CaF2/p-Si(111) capacitors: Evidence for an elastic electron tunneling through a thin (1-2Â nm) fluoride layer

Photon emission from the grown Au/CaF2/p-Si(111) structures is revealed under the positive substrate bias. This phenomenon occurs due to radiative transitions involving hot electrons injected into silicon. Behavior of light intensity within the selected spectral intervals gives evidence for an elastic tunneling transport through the ultra-thin dielectric film. The result is important considering a perspective of using the epitaxial fluorides as barrier layers in resonant tunneling diodes. Some data of electrical characterization are also included.