A large amount of work world-wide has been directed towards obtaining an understanding of the fundamental characteristics of porous Si. Much progress has been made following the demonstration in 1990 that highly porous material could emit very efficient visible photoluminescence at room temperature. Since that time, all features of the structural, optical and electronic properties of the material have been subjected to in-depth scrutiny. It is the purpose of the present review to survey the work which has been carried out and to detail the level of understanding which has been attained. The key importance of crystalline Si nanostructures in determining the behaviour of porous Si is highlighted. The fabrication of solid-state electroluminescent devices is a prominent goal of many studies and the impressive progress in this area is described.

The structural and luminescence properties of porous silicon

http://nathan.instras.com/documentDB/paper-69.pdf

Porous silicon: a quantum sponge structure for silicon based optoelectronics

Light emission from porous silicon and related materials

Photoluminescence and electroluminescence from porous silicon

This work reviews the use of porous silicon (PS) as a nanomaterial which is extensively investigated and utilized for various applications, eg, in the fields of optics, sensor technology and biomedicine Furthermore the combination of PS with one or more materials which are also nanostructured due to their deposition within the porous matrix is discussed Such nanocompounds offer a broad avenue of new and interesting properties depending on the kind of involved materials as well as on their morphology The filling of the pores performed by electroless or electrochemical deposition is described, whereas different morphologies, reaching from micro- to macro pores are utilized as host material which can be self-organized or fabricated by prestructuring For metal-deposition within the porous structures, both ferromagnetic and non-magnetic metals are used Emphasis will be put on self-arranged mesoporous silicon, offering a quasi-regular pore arrangement, employed as template for filling with ferromagnetic metals By varying the deposition parameters the precipitation of the metal structures within the pores can be tuned in geometry and spatial distribution leading to samples with desired magnetic properties The correlation between morphology and magnetic behaviour of such semiconducting/magnetic systems will be determined Porous silicon and its combination with a variety of filling materials leads to nanocomposites with specific physical properties caused by the nanometric size and give rise to a multiplicity of potential applications in spintronics, magnetic and magneto-optic devices, nutritional food additives as well as drug delivery

https://www.mdpi.com/1996-1944/3/2/943/pdf

Porous Silicon—A Versatile Host Material

Recently a quantum size effect was proposed to be responsible for the blue shift of optical absorption edge and photoluminescence peak wavelength as well as for the porous silicon (PS) formation itself. In the debate about the mechanism of light emission from PS a correlation between particle size and luminescence peak position would be a key test of the confinement approach. In this letter X-ray diffraction results of as-etched PS samples will be presented that indicate a decrease of particle size and an increase of stress in conjunction with a blueshift of photoluminescence wavelength and absorption edge.

https://iopscience.iop.org/article/10.1143/JJAP.32.2095/pdf

Barbara Jobst

Papers

Correlation between Optical Properties and Crystallite Size in Porous Silicon