Besides its main-stream programs, nanoMIR also carries out more fundamental studies to explore the full potential of the III-Sb technology. Some of these topics may become more important in the future or in contrast be dropped out. We give below a few examples of recent topics.
Staff: J.-B. Rodriguez, L. Cerutti, E. Tournié.
Collaborations: A. Trampert, E. Luna, PDI-Berlin (Germany); R. Kudrawiecz, University of Wroclaw (Poland).
Since 2016 we are investigating the incorporation of Bi in III-Sb alloys and heterostructures. Incorporating Bi in III-Sbs is challenging and it has been little studied. We elucidated the peculiar growth conditions needed to get high incorporation, and we achieved record the record incorporation of 14% in layers and quantum wells (QWs). We have demonstrated the first GaSbBi-based QW laser diode. It operated up to room temperature. We have also investigated GaInSbBi alloys and QWs, and demonstrated a competition between In and Bi incorporation. We have studied the microstructure and electronic properties of our samples in collaboration with the Paul Drude Institut of Berlin and the University of Wroclaw, respectively. All results can be found in a series of papers published in Applied Physics Letters, J. Applied Physics, J. Crystal Growth and Semiconductor Science and Technology.
Staff: J.-P. Perez, T. Taliercio, E. Tournié.
Collaborations : R. Vaillon, IES ; P.O. Chapuis, CETHIL Lyon.
The narrow bandgap of III-Sbs is well suited to TPV cells which aim at harvesting waste heat. Together with other IES colleagues, we are involved in a fundamental ANR project investigating near-field TPV, with the aim to demonstrate a several-fold efficiency enhancement under near field illumination.
Topological phases in InAs/GaSb quantum wells
Staff : E. Tournié, L. Cerutti, F. Gonzalez-Posada, J.B. Rodriguez
Collaborations : F. Teppe, L2C, Montpellier (France).
Surface states in semiconducting and insulating materials are usually fragile with respect to disorder and perturbations such as impurity scattering and many-body interactions. However, there are systems in which surface states are robust due to the non-trivial topology of the band structure. Recently, broken gap InAs/GaSb quantum wells have shown a topological insulating phase robust even to strong magnetic fields. We collaborate with our colleagues from the Physics Department (L2C, UMR CNRS 5221) to investigate these phases. Recent results can be found in Krishtopenko et al., Phys. Rev. B 99 (2019) 121405(R), JETP Letters 109 (2019) 96 – 101 and Phys. Rev. B 97 (2018) 245419.
Electrically-pumped Optical Parametric Oscillation
Staff: E. Tournié, L. Cerutti
PhD student: S. Roux (Thales Research and Technology, France, 2013 – 2016)
Collaborations: A. Grisard, Thales research and Technology-France, and B. Gérard, III-V lab, Palaiseau (France).
This ASTRID project aimed at the highly ambitious demonstration of electrically-pumped optical parametric oscillation in orientation-patterned III-Sb waveguides thanks to GaSb laser diodes co-integrated with Orientation-Patterned-GaSb waveguides. The joint implementation of III-Sb active structures emitting in the 2.0 – 2.5 µm wavelength range and of OP-GaSb waveguides efficiently converting this pump in the 2.5 – 12 µm wavelength range would offer a perfect match toward electrically-pumped monolithic semiconductor lasers sources with an unprecedented tuning capability. We have developed the individual cornerstones, but the project stopped before we could complete the whole device. More information can be found in Roux et al., Opt. Mater. Expr. 7 (2017) 3011 and Proc. SPIE 9894 (2016) 989415. This project is currently in standby.