Description du sujet de thèse

Missions
The goal of the project is to design, build and characterize infrared sensor operating in the short and extended short wave (i.e., up to 2.5 µm) and mid wave (3-5 µm) infrared range. While such device is already existing we now aim to render them post fabrication reconfigurable, which typically mean that their spectral response can be changed thanks to a knob such as a bias. Our preliminary results (see publications from the group in context section) show that such effect can be obtained by combining an inhomogeneous absorption map and a field dependent diffusion length. The latter effect comes from free thanks to hopping conduction, While the former is generated by a photonic cavity. Here the work will be to maximize the spatial inhomogeneity of the electromagnetic field using various type of cavity (plasmonic, dielectric) to generate new spectral shaping. Various spectral function will be targeted such as band selection, notch filtering…A long term goal will be to explore the transfer of such concept from single pixel device to imager.


Activities
*Fabrication of nanocrystal thin film
* Optical measurements for the characterization of thin film (microscopy, ellipsometry)
* Electromagnetic design of device using soft-ware such as FDTD software and finite element method
*Clean room fabrication (including e-beam lithography) including optical and electrical characterization
*Optoelectronic characterization of infrared sensor (I-V, photocurrent spectrum, time response, noise, cryogenic measurements)
*Punctual measurements on synchrotron might also be involved to determine device band structure and learn abouit material electronic structure
*Reporting of the results

Skills
The candidate will have a strong background in semiconductor physics. Experience in one of the following areas is desirable: nanophotonics, clean room manufacturing, measurement of electronic transport in cryogenic conditions, handling of colloidal nanocrystals. It is essential to have published scientific paper to apply. The candidate must have a strong appetite for experimental work (development of new instruments and measurement of characterization). The project is also very multidisciplinary with chemistry, physics of µ-fabrication and instrumentation. You don't have to be an expert on every subject, but be ready to learn on all aspect of the project. The candidate will have to work in an international team and therefore fluency in English is required.

Contexte de travail

Contexte
The PhD is funded ERC through the grant AQDtive
The work will be carried out at the “Institut des Nanosciences de Paris” (INSP) in the team of Emmanuel Lhuillier. The work will be done in collaboration with internal collaborator (other member of the group, engineer from the lab), collaborator from academic lab (in particular Onera and LPENS)



Publications from the group on the topic
1. Bias reconfigurable photoresponse of infrared nanocrystal film integrated into a coupled nano Fabry Perot resonator, T. H. Dang, C. Abadie, A. Chu, M. Cavallo, A. Khalili, C. Dabard, E. bossavit, H. Zhang, Y. Prado, D. Pierucci, J. K. Utterback, Y. Todorov, C. Sirtori, P. Bouchon, G. Vincent, A. Vasanelli, B. Fix, E. Lhuillier, ACS photonics 10, 1601 (2023)
2. Design Rules for Efficient Metallic Mid Infrared Transparent Electrode Dedicated to Nanocrystal-based Devices, T. H. Dang, M. Cavallo, A. Khalili, E. Bossavit, H. Zhang, Y. Prado, C. Abadie, E. Dandeu, S. Ithurria, G. Vincent, Y. Todorov, C. Sirtori, A. Vasanelli, E. Lhuillier, ACS Photonics 11, 1928 (2024)
3. Multiresonant Grating to replace Transparent Conductive Oxide Electrode for bias selected filtering of infrared photoresponse, Tung H. Dang, M. Cavallo, A. Khalili, C. Dabard, E. Bossavit, H. Zhang, N. Ledos, Y. Prado, X. Lafosse, C. Abadie, S. Ithurria, G. Vincent, Y. Todorov, C. Sirtori, A. Vasanelli, E. Lhuillier, Nano Lett 23, 8539 (2023)

Contraintes et risques

full time job at the lab
handling nanoparticles, laser, X-ray source