Sensors (May 2019)

UV Sensitivity of MOS Structures with Silicon Nanoclusters

  • Mario Curiel,
  • Nicola Nedev,
  • Judith Paz,
  • Oscar Perez,
  • Benjamin Valdez,
  • David Mateos,
  • Abraham Arias,
  • Diana Nesheva,
  • Emil Manolov,
  • Roumen Nedev,
  • Valeri Dzhurkov

DOI
https://doi.org/10.3390/s19102277
Journal volume & issue
Vol. 19, no. 10
p. 2277

Abstract

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Selective UV sensitivity was observed in Metal-Oxide-Semiconductor structures with Si nanoclusters. Si nanocrystals and amorphous Si nanoparticles (a-Si NPs) were obtained by furnace annealing of SiOx films with x = 1.15 for 60 min in N2 at 1000 and 700 °C, respectively. XPS and TEM analysis prove phase separation and formation of Si nanocrystals in SiO2, while the a-Si NPs are formed in SiO1.7 matrix. Both types of structures show selective sensitivity to UV light; the effect is more pronounced in the structure with nanocrystals. The responsivity of the nanocrystal structure to 365 nm UV light is ~ 4 times higher than that to green light at 4 V applied to the top contact. The observed effect is explained by assuming that only short wavelength radiation generates photocarriers in the amorphous and crystalline nanoclusters.

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