Master projects/internships - Leuven | More than two weeks ago
Advanced Sub-Micrometer Patterning Methods for Perovskite-based Lasers
Organometal halide and all-inorganic perovskite semiconductors have recently emerged as highly promising and inexpensive materials for solar cells, photodetectors, displays, and lasers. This rapid advancement has become possible due to their remarkable optoelectronic properties (direct bandgap and high absorption coefficient, sharp optical band edge, defect tolerance, high ambipolar carrier mobility) coupled to facile low-temperature processing such as spin-coating. ULTRA-LUX project and this work have the ambition to enable high-brightness perovskite-based light-emitting diodes and injection lasers. The realization of the latter would enable a variety of new applications such as industry-relevant on-chip light sources integrated into common CMOS photonic platforms, Lab-on-a-Chip devices, or advanced spectroscopy. To enable electrical lasing, perovskite semiconductors were selected over organic and colloidal quantum-dot active layers due to the lack of excessive losses of electron-hole pairs when pumped electrically.
To enable a lasing structure, perovskite gain medium must be integrated into the resonator that would support the light feedback. Among ultra-low-loss photonics resonators, distributed feedback (DFB) reflector has been widely studied to be incorporated in perovskite gain medium because of its single-mode operation and tunability. Due to the air and water instability of perovskite semiconductors and their susceptibility to most of the common solvents, the use of conventional wet-chemistry lithography techniques is very limited. To create DFB reflectors and other 2D photonic bandgap structures, we will utilize the bottom up and top-down nanoimprint lithography patterning methods that do not involve perovskite solvent exposure.
Together with senior colleagues, the selected candidate will apply the proposed patterning techniques to a variety of metal halide perovskites, characterize lasing and amplified spontaneous emission (ASE) thresholds together with other optoelectronic properties. Low ASE and lasing thresholds are among the most important metrics for a successful nanolithography process. We will further integrate obtained perovskite resonator structures into a complete electrical device to investigate the feasibility of electrical lasing using nanoimprint lithography.
Type of Work: combination of advanced (cleanroom) processing, electrooptical characterization, data processing, and literature study.
Type of Project: Internship, Thesis, Combination of internship and thesis
Master's degree: Master of Science, Master of Engineering Science, Master of Engineering Technology
Duration: 9 - 12 months
Imec allowance will be provided for students studying at a non-Belgian university.