Silicon emission technologies based on nanocrystals
Lead Research Organisation:
University of Manchester
Department Name: Electrical and Electronic Engineering
Abstract
The global semiconductor market has a value of around $1trillion, over 90% of which is silicon based. In many senses silicon has driven the growth in the world economy for the last 40 years and has had an unparalleled cultural impact. Given the current level of commitment to silicon fabrication and its integration with other systems in terms of intellectual investment and foundry cost this is unlikely to change for the foreseeable future. Silicon is used in almost all electronic circuitry. However, there is one area of electronics that, at the moment, silicon cannnot be used to fill; that is in the emission of light. Silicon cannot normally emit light, but nearly all telecommunications and internet data transfer is currently done using light transmitted down fibre optics. So in everyones home signals are encoded by silicon and transmitted down wires to a station where other (expensive) components combine these signals and send light down fibres. If cheap silicon light emitters were available, the fibre optics could be brought into everyones homes and the data rate into and out of our homes would increase enormously. Also the connection between chips on circuit boards and even within chips could be performed using light instead of electricity. The applicants intend to form a consortium in the UK and to collaborate with international research groups to make silicon emit light using tiny clumps of silicon, called nanocrystals;. These nanocrystals can emit light in the visible and can be made to emit in the infrared by adding erbium atoms to them. A number of techniques available in Manchester, London and Guildford will be applied to such silicon chips to understand the light emission and to try to make silicon chips that emit light when electricity is passed through them. This will create a versatile silicon optical platform with applications in telecommunications, solar energy and secure communications. This technology would be commercialised by the applicants using a high tech start-up commpany.
Publications
A P Knights (Author)
(2011)
Probing the formation of silicon nano-crystals (Si-ncs) using variable energy positron annihilation spectroscopy
Crowe I
(2013)
Donor ionization in size controlled silicon nanocrystals: The transition from defect passivation to free electron generation
in Journal of Applied Physics
Crowe I
(2010)
Spatially correlated erbium and Si nanocrystals in coimplanted SiO2 after a single high temperature anneal
in Journal of Applied Physics
Crowe I
(2011)
Probing the phonon confinement in ultrasmall silicon nanocrystals reveals a size-dependent surface energy
in Journal of Applied Physics
Iain F. Crowe (Author)
(2010)
Formation of Si-nanocrystals in SiO
Ishii M
(2013)
Atomic-scale distortion of optically activated Sm dopants identified with site-selective X-ray absorption spectroscopy
in Journal of Applied Physics
Ishii M
(2012)
Investigation of the thermal charge "trapping-detrapping" in silicon nanocrystals: Correlation of the optical properties with complex impedance spectra
in Applied Physics Letters
Ishii M
(2014)
Luminescence quenching of conductive Si nanocrystals via "Linkage emission": Hopping-like propagation of infrared-excited Auger electrons
in Journal of Applied Physics
Ishii M
(2014)
Electrical observation of non-radiative recombination in Er doped Si nano-crystals during thermal quenching of intra-4f luminescence
in Japanese Journal of Applied Physics
Description | we were able to improve the incorporation of erbium into silicon oxide with applications to telecomms market. The use of Bismuth as a light emitter was shown to be ineffective due to out diffusion. The use of rapid thermal processing was shown to control the size of silicon nanocrystals and tune their emission wavelength. Phosphorus doping of silicon rich oxide was shown to be effective as a dopant and also to act as a surfactant passivating the surface layers. |
Exploitation Route | could be of use in the photovoltaic field, the process developed has been used by the US renewable energy laboratory for improved energy harvesting in Silicon based solar cells |
Sectors | Energy |
Description | The findings have been used to improve the understanding of the formation of silicon nanoclusters in the presence of rare -earth ions. Also the effect of phosphorus doping of silicon rich oxide layers has been advanced considerably. This work hasd been cited by researchers at the renewable energy labs in the US in their work to make multijunction silicon based cells |
First Year Of Impact | 2013 |
Sector | Education,Energy |
Impact Types | Cultural Societal |
Description | QinetiQ |
Organisation | Qinetiq |
Country | United Kingdom |
Sector | Private |
PI Contribution | Samples were processed using facilities as Qinetiq, research reports were read by qinetiq staff |
Collaborator Contribution | processing was provided by Qinetiq |
Impact | the collaboration was basen on exchange of information on Graphene between Manchester and Qinetiq. |
Start Year | 2010 |