An essential tool supporting the development of new materials and structures for opto-electronic devices is the characterization and detailed understanding of their optical properties. The spectroscopy and recombination dynamics (SpeRe) activity in LPN-GOSS aims at providing fine spectroscopic information on all kind of semiconductor structures using low temperature photoluminescence (PL), excitation spectroscopy (PLE), photocurrent spectroscopy or optical absorption over a very broad spectral domain (0.7 eV 3 eV), as well as information on the recombination dynamics using a time resolved set-up (4ps temporal resolution). Reactivity and openness to emerging topics, within LPN and beyond, are the key words of this service to the community, that also includes modeling of the results using dedicated tools, in particular a versatile transfer-matrix code. Recent studies involve new materials based on III-V semiconductors (quantum dots, ultrashort period superlattices, nanowires ) as well as more exotic materials like hybrid organic-inorganic perovskites. Time resolved spectroscopy is also an important tool to assess the quality of materials for laser applications and to test the side effects of processing, for instance non radiative recombination due to etching damages.
Reference contract : LIA
Coordinator, Partner(s) : F. Glas (LPN ),
LPN leader(s): Frank Glas
Main goals : Organize and develop scientific collaborations between the CNRS laboratories and the laboratories and institutes of the Russian Academy of Sciences based in Saint Petersburg in the domains of growth and study of the physical properties of nanostructures of compound semiconductors, and of compounds based on the latter.
Reference contract : ANR Blanc
Coordinator, Partner(s) : E. Deleporte (LPQM ), J. Even (FOTON ), P. Audebert (PPSM )
LPN leader(s): Jacqueline Bloch, Sophie Bouchoule
Main goals : Vertical microcavities in the light-mater strong coupling are intensively studied due to the interest in coherent and stimulated effects in such systems as polariton lasing and Bose Einstein condensation in the solid phase. These effects have been recently demonstrated in “classical” inorganic semiconductors and most of the physics is done at low temperature. Until now, attempts to study these physical processes with molecular materials have failed.In this draft, we propose to use organic-inorganic molecular quantum wells inside a vertical microcavity to demonstrate stimulated effects at room temperature. The molecular quantum wells used in this study belong to the perovskite family. Because the strong coupling regime in vertical microcavities containing perovskites has been achieved at room temperature and because of the wide tunability of its exciton perovskite material is a good candidate to realize vertical microcavities and study these polaritonic effects. The physics of these new polaritons is unexplored. Therefore, polariton relaxation efficiency and dynamics will be studied. Finally, experiments designed to observe stimulated effects on these polariton states will be performed. Partners : LPQM-ENS Cachan (project leader), LPN, PPSM-ENS Cachan, FOTON-INSA Rennes (2010-2014)