The Electrochemistry of Porous Semiconductors

2009 ◽  
pp. 249-278
Author(s):  
John J. Kelly ◽  
A.F. van Driel
Keyword(s):  
Porous Semiconductors

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

scholarly journals MODELING AND INVESTIGATION OF SCHOTTKY DIODES BASED ON POROUS SEMICONDUCTORS

2019 ◽  
Vol 5 ◽  
pp. 148-154
Author(s):  
А. Oksanich ◽  
◽  
М. Kogdas ◽  
V. Chebenko ◽  
M. Maschenko ◽  
...  
Keyword(s):  
Schottky Diodes ◽  
Porous Semiconductors

scholarly journals Optical Losses in Hybrid Microcavity Based in Porous Semiconductors and its Application as Optic Chemical Sensor

2019 ◽  
Vol 56 ◽  
pp. 158-167
Author(s):  
Claudia Antonio Hernández ◽  
Edith Osorio ◽  
Raúl Urteaga ◽  
Roberto Koropecki ◽  
José Alberto Alvarado ◽  
...  
Keyword(s):  
Chemical Sensor ◽  
Visible Region ◽  
Bragg Reflector ◽  
Resonant Peak ◽  
Light Sources ◽  
Optical Losses ◽  
Distributed Bragg Reflector ◽  
Nanoporous Anodic Alumina ◽  
Porous Semiconductors ◽  
Point Light

In this study the experimental and theoretical optical analysis of a hybrid microcavity (HM) based in porous silicon (PS) and nanoporous anodic alumina (NAA) are presented. The microcavity was centered in the visible region at 760 nm. Distributed Bragg reflector (DBR) was obtained using galvanostatic anodizing method and while NAA by the two-step anodization technique. From SEM micrographs the HM different regions are observed. HM optical characterization in the visible region was done, considering two different light sources, point and non-point respectively. These results reveal a decrease in the quality factor (Q) from 350 to 190 when the source is exchanged; this behavior has been mainly attributed to the light scattering at NAA. Furthermore, it was possible to study Q change, through transmittance simulation using the transfer matrix and Landau-Lifshitz-Looyenga theoretical methods. When a point light source is used, there are no optical losses making possible to sense 1% of analyte resulting in a 0.29 nm redshift of the resonant peak. According with these results we propose to apply the HM as chemical optic sensor.

Porous and Nanoporous Semiconductors and Emerging Applications

2005 ◽  
Vol 876 ◽  
Author(s):  
Helmut Föll ◽  
Jürgen Carstensen ◽  
Stefan Frey
Keyword(s):  
Optical Properties ◽  
Fuel Cells ◽  
Pore Formation ◽  
Large Area ◽  
Paper Briefly ◽  
High Explosives ◽  
Single Crystalline ◽  
Natural Materials ◽  
Porous Semiconductors ◽  
Wide Range

AbstractPores in single crystalline semiconductors can be produced in a wide range of geometries and morphologies, including the “nano” regime. Porous semiconductors may have properties completely different from the bulk, and metamaterials with e.g. optical properties not encountered in natural materials are emerging. Possible applications of porous semiconductors include various novel sensors, but also more “exotic” uses as, e.g. high explosives or electrodes for micro fuel cells. The paper briefly reviews pore formation (including more applied aspects of large area etching), properties of porous semiconductors and emerging applications.

Are Slit Pores in Carbonaceus Materials Real?

2009 ◽  
Vol 1216 ◽  
Author(s):  
Cristina Romero ◽  
Ariel A. Valladares ◽  
R. M. Valladares ◽  
Alexander Valladares
Keyword(s):  
Ad Hoc ◽  
Computational Cost ◽  
Experimental Results ◽  
Pore Model ◽  
Graphene Layers ◽  
Porous Semiconductors ◽  
Carbon Chains ◽  
Slit Pore ◽  
Potential Applications ◽  
Slit Pores

AbstractNanoporous carbon is a widely studied material due to its potential applications in hydrogen storage or for filtering undesirable products. Most of the developments have been experimental although some simulation work has been carried out based on the use of graphene sheets and/or carbon chains and classical molecular dynamics. The slit pore model is one of the oldest models proposed to describe porous carbon. Developed by Emmet in 1948 [1] it has been recurrently used and in its most basic form consists of two parallel graphene layers separated by a distance that is taken as the width of the pore. Its simplicity limits its applicability since experimental evidence suggests that the walls of the carbon pores have widths of a few graphene layers [2], but it still is appealing for computational simulations due to its low computational cost. Using a previously developed ab initio approach to generate porous semiconductors [3] we have obtained porous carbonaceous materials with walls made up of a few graphene layers (four layers), in agreement with experimental results; these walls are separated by distances comparable to those used in the slit pore model [4]. This validates the idea of a modified slit pore model obtained without the use of ad hoc suppositions. Structures will be presented, analyzed and compared to available experimental results.

scholarly journals Regiocontrolled dimerization of asymmetric diazaheptacene derivatives toward X-shaped porous semiconductors

2020 ◽  
Vol 11 (41) ◽  
pp. 11235-11243
Author(s):  
Guowei Zhang ◽  
Ning Xue ◽  
Wen Gu ◽  
Xingzhou Yang ◽  
Aifeng Lv ◽  
...  
Keyword(s):  
Porous Materials ◽  
Open Channels ◽  
Porous Semiconductors

The synthesis of conformationally rigid X-shaped PAHs by regiocontrolled cyclodimerization of diazaheptacene diimides is presented. The resulting porous materials exhibit enhanced semiconducting behaviors with large open channels.

Porous Semiconductors: A Tutorial Review

1996 ◽  
Vol 452 ◽  
Author(s):  
L T Canham
Keyword(s):  
Knowledge Base ◽  
Porous Si ◽  
Porous Semiconductors ◽  
To Receive

AbstractPorous semiconductors constitute a class of material that exhibit surprising properties, are quite easy to fabricate, but are however fragile, complex, and difficult to characterise. This tutorial review extracts specific topics from the large knowledge base now available on porous Si that are deemed relevant to other porous semiconductors beginning to receive study. It also highlights topics where controversy is now resolved, where problems remain, and where further effort could be focused.

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