Specific Blue Light Emission from Nanocrystalline Porous Si Treated by High-Pressure Water Vapor Annealing

Abstract

The effects of a combination of thermal oxidation at various temperatures and high-pressure water vapor annealing (HWA) on the luminescence and structural characteristics of nanocrystalline porous Si (PSi) have been investigated. The influences of initial PSi porosity and excitation power have also been studied. Strong, stable, and single-band blue emission was obtained when PSi was first treated by thermal oxidation above 800 C and then by HWA. This blue emission can coexist with the conventional red emission band of Si nanocrystals when PSi is not sufficiently oxidized. The blue emission may originate from localized states in the Si oxide or at the silicon/ oxide interface. HWA very efficiently boosts the emission from these localized states by increasing the quality of the oxide network. This result is useful for the realization of short-wavelength Si-based optoelectronic devices.

Photoluminescence‐Based Sensing With Porous Silicon Films, Microparticles, and Nanoparticles

“…Rapid thermal oxidation in a high temperature furnace was the first method shown to provide very stable, highly luminescent porous Si, [140] and there are now several effective oxidation recipes that can be followed. [143][144][145][146] However, the more corrosive oxidants such as halogens, NO, NO 2 , ozone, and in some cases O 2 can react with porous Si to destroy luminescence. [91,[147][148][149][150] The degradation in luminescence can be attributed to the generation of defective oxides at the surface of the porous Si nanocrystallites.…”

Silicon Nanocrystals in Porous Silicon and Applications

“…The last approach can be used to produce efficient blue PL [214]. By using a combination of thermal annealing and highpressure water vapor annealing, samples emitting only blue (without any contribution of the red-emitting S-band) bright PL can be produced [215]. This blue emission can be divided in two main contributions.…”

(Invited) Blue Phosphorescence in Oxidized Nano-Porous Silicon

“…More recently, we demonstrated efficient blue PL from partially oxidized PSi (9). This blue emission includes an intrinsic phosphorescence (Ph) band which exhibits a lifetime of several seconds because of radiative transitions from triplets to ground states (10).…”