Silicon Light-Emitting Nanostructures
Preparation and Investigation in Physical Properties of Light-Emitting Nanostructures Based on Silicon Nanowires and Nanocrystals
Tech Area / Field
- PHY-SSP/Solid State Physics/Physics
- INF-ELE/Microelectronics and Optoelectronics/Information and Communications
8 Project completed
Senior Project Manager
Russian Academy of Sciences / Institute of Crystallography, Russia, Moscow
- Russian Academy of Sciences / Institute of Radioengineering and Electronics, Russia, Moscow
- Lawrence Livermore National Laboratory, USA, CA, Livermore\nLos-Alamos National Laboratory / Physical Chemistry and Applied Spectroscopy Group, MS-J585, USA, NM, Los-Alamos\nHanyang University, Korea, Seoul
Project summarySilicon integrated microelectronics is a basis of the modern progress in science and technology. The principal trend in the silicon integrated microelectronics is a reduction of electronic components sizes. Currently, the feature size is 0.1 - 0.3 m, and the value is continuously decreasing. This results in significant enlargement of the packing density of the electronic components in integrated circuits. Accordingly, the length of interconnections is also strongly increased resulting in strongly increased propagation time of the electrical signals in the circuits and between circuits.
A possible solution of the problem is the use of optical circuits as interconnects between different electronic components. In order to realize such an approach, silicon light emitting diodes or injection lasers compatible with the silicon integral microelectronics are required. Light emitting silicon devices could also open way to realization of silicon optoelectronics.
However, the preparation of the light-emitting silicon devices represent a hard problem. Because of the indirect energy gap, bulk silicon is not an effective light emitter. Therefore, during the last decade extensive studies of low-dimensional silicon nanostructures (porous silicon, nanocrystals of silicon in SiO2 matrix, etc.) have been undertaken. Effective photoluminescence (PL) and electroluminescence (EL) in the visible spectral range at both room and cryogenic temperatures have been observed in these systems.
This project is devoted to the development of new approaches to fabrication of light-emitting devices based on silicon-nanostructures.
One of the proposed approaches consists in preparation of silicon nanostructures in the form of an array of mutually parallel single-crystalline silicon nanowires. The approach is based on the growing oriented arrays of silicon filamentary crystals (single-crystalline whiskers) on the single-crystalline silicon substrates by a vapor-liquid-solid (VLS) method that was previously developed by one of the participants of the project (Institute of Crystallography, Russian Academy of Sciences, Moscow).
Another approach to the preparation of the array of the silicon nanowires is based on the application of electron lithography to the silicon substrate with subsequent deep plasmo-chemical etching.
One more approach to preparation of light-emitting silicon nanostructures is based on the technology that has been developed during the past several years by another participant of the project (Institute of Radioengineering and Electronics, Russian Academy of Sciences). The approach consists in preparation of an array of the silicon tips on the silicon substrate with subsequent coating this array by a layer that contains silicon nanocrystals embedded in a dielectric matrix (SiOx, Si3N4 or SiOxNy). The array of the silicon tips will be prepared from the single-crystalline silicon whiskers as described above.
In this project we propose to perform detailed studies of structural, electrical, and optical properties of silicon nanostructures described above. Specifically, we will concentrate on the physical mechanisms for the PL and EL in these silicon nanostructures. As a part of this work, we will study the mechanisms for charge carrier transport in arrays of quantum nanowires across a broad range of temperatures and electrical fields as well as photoconductivity in the broad range of spectral energies. These fundamental studies will guide our fabrication efforts allowing optimization of the PL and EL properties of silicon nanostructures.