Framework and context: MicroLEDs based on III nitride semiconductors are promising candidates for next generation display and optoelectronic technologies. Their performance is strongly influenced by carrier recombination and transport processes occurring at the nanoscale, particularly in the vicinity of sidewalls, interfaces and material defects. Time Resolved Cathodoluminescence (TRCL) is a powerful technique combining the high spatial resolution of electron microscopy with time and spectrally resolved luminescence measurements. It enables the investigation of local carrier dynamics and luminescence properties with nanometric spatial and sub nanosecond temporal resolution. The objective of this internship is to develop and apply TRCL characterization methodologies to III nitride microLEDs with a particular focus on understanding spatial variations in luminescence and carrier dynamics.

Work description: 

The work will include:
1. Development and optimization of TRCL measurement protocols for microLED characterization including the control of electron beam energy, beam current and sample temperature,
2. Investigation of carrier dynamics in microLED structures with particular attention to the influence of device dimensions, sidewalls, interfaces and material defects,
3. Data processing and analysis of multidimensional TRCL datasets, combining spatial, spectral and temporal information, and correlation with complementary characterization techniques such as Time Resolved Photoluminescence and Kelvin Probe Force Microscopy.

The applicant must be strongly motivated to learn how to handle advanced facilities and analyze the data. He will have the opportunity to develop transverse skills as the work will be carried out with academic collaborators, and will involve issues of intellectual property, industrial experience with the LETI partners and a daily practise of English. Proper background in solid state physics is essential. Basic knowledge about luminescence techniques is not mandatory but will be appreciated.

Possible continuation as a PhD thesis. Depending on the results of the internship and the candidate's performance, the internship may lead to a PhD thesis starting after the internship.