Anodic oxidation of p- and p+-type porous silicon: surface structural transformations and oxide formation

ABSTRACTThe photoluminescence (PL) observed from porous silicon (PS) is found to be very sensitive to pH. Brønsted bases quench the PL and simultaneously produce a blue shift of the p-type PS emission. Similarly, PL of n-type PS is quenched, but the emission is red shifted. Exposure to acids enhances PL and reverses the quenching due to base exposure. A pKa of 3–4 was determined for PS formed on both n- and p-type substrates, and identifies an acidic surface proton as a primary component in the PL mechanism. Variations in the intensity and energy distribution of PL as a function of temperature suggest that: 1) small changes in the hydration state of the surface may affect the emission, and 2) at least two luminescent species exist on the surface of PS; one of which is pH and temperature sensitive. SO2, a Lewis base, also quenches the PL of p-type PS quickly and reversibly. Exposure to acid is unnecessary for restoration of the PL. In contrast to reactivity with Brønsted bases, the reversibility with SO2 argues for a different quenching mechanism. Preliminary experiments show that PL is significantly quenched, ∼2–5%, by concentrations of ∼30ppm SO2 in Ar.

Download Full-text

Angular Ellipsometry of Porous Silicon Surface Layers

Journal of Nano- and Electronic Physics ◽

10.21272/jnep.12(3).03024 ◽

2020 ◽

Vol 12 (3) ◽

pp. 03024-1-03024-4

Author(s):

L. V. Poperenko ◽

◽

S. G. Rozouvan ◽

I. V. Yurgelevych ◽

P. O. Lishchuk ◽

...

Keyword(s):

Porous Silicon ◽

Silicon Surface ◽

Surface Layers ◽

Porous Silicon Surface

Download Full-text

Enhancement of the photoluminescence property of hybrid structures using single-walled carbon nanotubes/pyramidal porous silicon surface

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2017.10.040 ◽

2018 ◽

Vol 731 ◽

pp. 978-984 ◽

Cited By ~ 8

Author(s):

Haythem Gammoudi ◽

Fatma Belkhiria ◽

Kamel Sahlaoui ◽

Walid Zaghdoudi ◽

Mahmoud Daoudi ◽

...

Keyword(s):

Carbon Nanotubes ◽

Porous Silicon ◽

Silicon Surface ◽

Photoluminescence Property ◽

Single Walled Carbon Nanotubes ◽

Hybrid Structures ◽

Single Walled Carbon ◽

Porous Silicon Surface ◽

Walled Carbon Nanotubes

Download Full-text

Chemical Modification of the Porous Silicon Surface

MRS Proceedings ◽

10.1557/proc-358-387 ◽

1994 ◽

Vol 358 ◽

Cited By ~ 12

Author(s):

Eric J. Lee ◽

James S. Ha ◽

Michael J. Sailor

Keyword(s):

Porous Silicon ◽

Chemical Modification ◽

Formic Acid ◽

Gas Phase ◽

Silicon Surface ◽

Chemical Vapor ◽

Luminescence Quenching ◽

Porous Silicon Surface ◽

Phase Water ◽

Surface Modified

ABSTRACTThe porous silicon (PS) surface is derivatized with ethanol, triethylsilanol and formic acid as well as oxidized with water. The two reactions used to prepare these surfaces are discussed, and FTIR spectra of the products are presented. Surface-modified PS retains 10-40% of its original photoluminescence. PS-derivatives display reversible luminescence quenching by gas phase water, ethanol, acetonitrile and benzene. The extent of quenching varies with different PS-derivatives depending on the interaction of the chemical vapor with the modified PS surfaces.

Download Full-text