Dual mechanism of photoresponse in composite Si-Au nanolayers on crystalline silicon.

Silicon-based structures comprised of crystalline silicon substrates and active layers of mixed silicon and gold nanoparticles were fabricated and characterized. Several layer compositions were studied. The investigated structures demonstrate very large spectral sensitivity (more than 10 A W⁻¹) in the wide spectral range (400-1000 nm). Such large sensitivity implies presence of photocurrent amplification. A model which involves dual mechanism of the photoresponse was proposed in order to explain the appearance of the photocurrent amplification in the investigated structures. Spectral sensitivity of the structure with composite layer of Si and Au nanoparticles on Si substrate (Au volume fraction is ∼50%) at reverse bias voltage of −0.4 V. [ABSTRACT FROM AUTHOR]