Recently, the thin-film materials used in the flat panel display industry (such as organic semiconductors for OLEDs) show promise to be combined with silicon circuitry, enabling new cross-over applications. One of these applications are imagers, where the photo-active material is a thin-film stack deposited on top of a CMOS read-out chip. These thin-film semiconductor materials can be considered 'soft' compared to covalent bonded silicon crystals and, therefore, have specific electronic properties. At imec, we are introducing the 'soft' materials into standard semiconductor cleanroom facilities to enable mass-manufacturing of novel imagers, such as near-infrared to short-wave infrared detectors with super-high resolution and multi-spectral sensitivity. A thorough understanding of the electronic structure of these materials as well as the interactions between the thin-film layers is needed in order to improve the performances of these imager devices.
The purpose of this PhD is to obtain a full description of the electronic band structure (including band alignment) of the thin-film layer stacks for photodiodes. These thin-film semiconductors are deposited from either solution (polymer semiconductors, metal-oxides or colloidal quantum dots) or by evaporation (organic small molecules, metal-oxides). A full photodiode stack consists of a minimum of 5 different materials and at each material interface, the energy alignment will influence the key performance figures of the photodiode. This PhD therefore has as goal to determine a) the energy structure of the used 'soft' materials and b) the interfacial effects between the layers, in order to optimize the photodiode device performance. This PhD is a collaboration between the Thin Film Electronic groups and the Material Characterization group and the PhD student will be involved in both the fabrication of the layers in our dedicated thin-film labs as well as in-depth characterization using mainly Photo Electron Spectroscopy measurements (UPS, XPS, HAXPES).
You are a highly motivated recent graduate holding a master's degree in nano-engineering, physics, material science, electrical engineering, or related. You have an interest in the processing of thin-film semiconductors, electrical and optical characterization and in-depth material study. You will be expected to work safely in a cleanroom environment and acquire processing and lab skills. It is expected that you will present results regularly. You are a team player and have good communication skills as you will work in a multidisciplinary and multicultural team spanning several imec departments. Given the international character of imec, an excellent knowledge of English is a must.
Required background: nano-engineering, physics, materials science or electrical engineering with strong affinity for material analysis
Type of work: 10% literature study, 20% modeling, 20% processing, 50% characterization
Supervisor: Paul Heremans
Daily advisor: David Cheyns, Thierry Conard
The reference code for this position is 2020-108. Mention this reference code on your application form.
Chinese nationals who wish to apply for the CSC scholarship, should use the following code when applying for this topic: CSC2020-57.