One of the fundamental targets that must be met for the project to have any chance of success will involve the development of new semiconductor materials. Such materials will be needed so lasers and other photonic components can be designed and produced to be more energy efficient and better able to operate in high temperatures. Such power reductions are considered an imperative as optical communication systems become the principal way to provide increasingly data-rich broadband services to homes and businesses.
Many of today’s photonic components used in telecommunications applications have major intrinsic losses. For example, around 80% of the electrical power used by a laser chip is emitted as waste heat. The fact that this waste heat is generated means thermo-electric coolers and air-conditioned environments have to be employed to control device temperature, further increasing power consumption.
The energy losses are largely due to a process called Auger recombination, where the recombination of an electron and a hole occurs in which no electromagnetic radiation is emitted, and the excess energy and momentum of the recombining electron and hole are given up to another electron or hole. This energy-losing sequence is attributed to the band structure of the semiconductor materials used in making components such as semiconductor lasers and optical amplifiers. Numerous attempts over many years have failed to reduce the energy inefficiencies caused by the Auger recombination process.
With this in mind, BIANCHO proposes a radical change of approach involving the elimination of Auger recombination by manipulating the electronic band structure of the semiconductor materials through the use of dilute bismide and dilute nitride alloys of gallium arsenide (GaAs) and indium phosphide (InP).
Comprising indium and phosphorus, InP features a higher electron velocity than more commonly used semiconductor materials such as silicon and GaAs. It also has a direct band gap, which makes it very useful in the design of optoelectronics devices like laser diodes.
BIANCHO believes the use of GaAs and InP will create more efficient and temperature-tolerant photonic devices capable of operating without the power-hungry cooling equipment that today’s networks demand.
The project brings together five European partners with expertise in epitaxy, structural characterization of materials, device physics, band structure modeling, advanced device fabrication, packaging, and commercialisation.
Coordinated by the Tyndall National Institute (Ireland), which is recognised for its work in semiconductor band structure modeling, BIANCHO’s other academic partners include Philipps Universitaet Marburg (Germany), focusing on material growth and characterisation; Semiconductor Research Institute (Lithuania), responsible for the design, manufacture, and characterisation of bismide-based epitaxial structures; and the University of Surrey (U.K.), which will contribute characterisation facilities and modeling expertise.
Commercialisation of the project’s results will be led by CIP Technologies (U.K.), an organisation with a long history of applied photonics innovation, particularly in the telecommunications sector.