Analysis of surface plasmon polariton enhancement in photodetection by Al-GaAs Schottky diodes

I. R. Tamm*, P. Dawson, A. Sellai, M. A. Pate, R. Grey, G. Hill

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


The surface plasmon polariton mediated photoresponse from Al-GaAs diodes is examined in a prism-air gap-diode configuration as a function of both the wavelength of the incident light and thickness of the Al electrode. The experimental data shows a pronounced dip in reflectance as a function of internal angle of incidence in the prism, due to the excitation of the surface plasmon polariton at the Al-air interface, and a corresponding peak in device photosignal. Careful modelling of reflectance and quantum efficiency data shows that the bulk of the signal is generated by light which is re-radiated from this surface mode into the semiconductor substrate where it is absorbed by the creation of electron-hole pairs in the depletion region. This holds for all the wavelengths used here (all are shorter than the GaAs absorption edge) and across the thickness range of the Al electrodes (20-50 nm). Quantum efficiencies in the range 0.5-22% and enhancement factors of typically 7.5 were recorded in this investigation.

Original languageEnglish
Pages (from-to)1417-1427
Number of pages11
JournalSolid State Electronics
Issue number10
Publication statusPublished - Oct 1993
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry


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