On the mechanism of photon emission from thin film tunnel structures

Abstract

The light emission from AI--AI2Os--M planar tunnel diodes was investigated where M = Ag, Au or Cu. Experiments on smooth and periodieally corrugated (holographie grating) substrates showed that the emitted light originates from surface plasmons seattered by the surface roughness and, probably, from the bremsstrahlung of tunneling eleetrons. AII the three noble metals show qualitatively similar behaviour and their light emission can be described as the superposition of three independent sources. The quantum effieiency of radiation was found to be ~10 -s photon/eleetron, elose to the theoretieal limit.

Electrical-Driven Plasmon Source of Silicon Based on Quantum Tunneling

“…Thus, the outstanding challenge is to understand the underlying light-creation mechanisms based on inelastically-tunneling electrons. Moreover, the spectral observations from [22] are inconsistent to other reports, and the originally anticipated quantum condition (E emission = hv = qV bias (1) [23], where v is the frequency, q the charge, V bias the applied voltage bias, and h Planks constant) is experimentally not validated [20,22,24,25]. The argument of a convolution between the spectral-dependent tunnel current and the device-internal plasmon was made to explain the deviation from (1), as further validated in results presented here [26].…”

“…Moreover, the spectral observations from ref 23 are inconsistent to other reports, and the originally anticipated quantum condition (E emission = hv = qV bias , 24 where v is the frequency, q the charge, V bias the applied voltage bias, and h Planck constant) is experimentally not validated. 19,23,25,26 This can be attributed to the fact that (a) increasing the electron energy distribution via hot carriers can change the quantum condition (e.g., hv > qV bias ), 26 which is a first order effect, and (b) the emission is governed by the overlap integral of the energy-dependent tunnel current with the modal dispersion. The argument of a convolution between the spectral-dependent tunnel current and the device-internal plasmon was made to explain the deviation from hv = qV bias , as further validated in results presented here.…”