Hybrid photonics is a new emerging research area at the interface between traditional optoelectronics and quantum technologies that spans a wide range of research areas from fundamental physics to applications of phenomena related to hybrid light-matter excitations and photon-mediated interactions of disparate material systems.
Purpose: optical study of hybrid nano-structures based on colloidal nanocrystals and organic semiconductors; integration of such materials into hybrid optoelectronic devices (light emitting diodes, LEDs, and photovoltaic cells, PVs); study of strong coupling in organic and inorganic microcavity structures; polaritonics and polariton Bose Einstein Condensates; polariton-based quantum simulators
The activities of the hybrid photonics labs are oriented towards two main research areas, hybrid optoelectronics and polaritonics.
Mainly focusing on photovoltaics and solid state lighting applications, the hybrid optoelectronics research on-going in the Hybrid Photonics Labs aims at integrating low-cost colloidal nanocrystalline materials (quantum dots) into existing solid state technologies. While these novel materials can provide very interesting properties (such as very high absorption cross-sections, near-unity luminescence quantum yields and band-gap tuneability), an inherent drawback is the difficulty to extract or inject carriers into these materials. Our research uses various energy transfers such a resonant energy transfer to funnel carriers between monocrystalline emitters and bulk semiconductors. We leverage numerous collaborations with key industrial players to design and produce novel hybrid technologies capable of enhancing the properties of standard optoelectronics devices.
Our research on hybrid PVs is currently focused on several key thin-film photovoltaic technologies, encompassing both traditional materials (thin-film Silicon, Cadmium-Telluride) and emerging systems (Perovskites). Hybrid structure are designed and fabricated in close collaboration with various fabrication research groups and industrial partners in the world such as the University of Liverpool in the UK or NCTU and Arima Corp. in Taiwan. Structure are fully characterized (internal/external quantum efficiency, carrier lifetime, photon conversion efficiency) in our facilities. Advanced spectroscopic techniques such as time-resolved photoluminescence are also used to gain critical insight into the energy transfers occurring between the various materials constituting the hybrid devices (colloidal QD, bulk p-n junction, window layer, etc.). In a recent achievement, we developed new technology that utilizes cheap colloidal quantum dots to recycle the carriers trapped in the top window layer of InGaP solar cells, yielding a 15% relative improvement in photon conversion efficiency.
Schematic representation of a hybrid InGaP solar cell (left) and J-V characteristics (right) of the solar before (black) and after (red) hybridisation.
M. Brossard et al., Adv. Opt. Mat., 2015
Our latest achievement was for instance the demonstration of record color-conversion efficiencies in white LEDs, in collaboration with TSMC and Luxaltek in Taiwan. This was done by designing a completely novel type of LED architecture, integrating complex photonic crystals structures and integrated nanocrystallinne emitters. The Hybrid Photonics Labs in Skoltech allow us to fully characterize these novel materials, but more importantly to further our understanding into how they interact when integrated into devices.
A televised report of recent achievements on hybrid LEDs can be seen in the following link (41:30).
The nature of large complex quantum-mechanical systems remains one of the most important question of modern physics, with applications in condensed-matter physics, high-energy physics, atomic physics, quantum chemistry etc. Current many body problems are extremely difficult to model analytically and often cannot be simulated accurately even by using very significant computing power. However, this difficulty may be overcome via some controllable quantum system (Quantum Simulator) exhibiting the same properties as a real system. Today a number of quantum systems such as neutral atoms, ions, polar molecules, electrons in semiconductors, superconducting circuits, nuclear spins, and photons have been proposed as quantum simulators. The polariton platform is one of the most promising. Solid-state microcavities based on semiconductor materials can allow the hybridization of excitations of matter (excitons) and photons in a cavity, forming mixed light-matter quantum quasi-particles, so-called polaritons. Under the certain circumstances in a strong coupling regime, polaritons start following Bose-Einstein statistics and condense in the ground state with identical energy and momentum (so-called Bose-Einstein condensation). The condensate being a macroscopic object (more than a thousand polaritons in the condensate), its quantum properties makes it a highly attractive building-block material for large scale quantum simulators. From this perspective, polariton condensate lattices can reproduce the complex nature numerous quantum systems such as magnetic systems with random Dzyaloshinskii-Moriya interactions, disordered Josephson junction arrays, disordered electron solids, vortex glasses in high-Tc cuprate superconductors, Mott insulators with orbital degrees of freedom, frustrated magnets, etc. The ability to work at room temperature is one of the major advantage of the polariton platform, in contrast to well-known superconductive qubits (SQUIDs) and simulators based on trapped ions which required a very low, sub-Kelvin temperature. Recent results of Prof. Lagoudakis and coworkers have demonstrated the great potential of polaritonics for quantum simulations. Our efforts are focused on the development of polariton-based simulators, with a focus increasing the system’s size and complexivity, while designing new methods to handle polariton condensates and studying complex quantum systems.
The Hybrid Photonics Labs currently consist of a large optical laboratory, hosting numerous laser sources and experimental. Several high power amplified Ti:Sapphire laser systems operating at 1 to 300kHz are available with pulse energies up to 5mJ over durations of <50fs to tens of picoseconds. Non-linear optical amplification and mixing can be used to provide users with tunable radiation between 200nm and 10µm. The facilities also houses a versatile collection of high power tunable Ti:Sapphire oscillators with repetition rates up to 80MHz allowing the rapid characterization of excitation wavelength dependent material properties.
The optical laboratories are also supported by ISO 7 (class 10000) cleanrooms. These facilities host an array of basic microfabrication and characterization tools. Closely interlinked with the optical laboratories, the cleanrooms allow users to fabricate and characterize samples before rapidly transferring them into the optical laboratories for further analysis.