Project is carried out within the TeamTech programme of the Foundation for Polish Science. Programme TEAM-TECH is co-funded in the framework of Program Operacyjny Inteligentny Rozwój (PO IR) oraz Foundation for Polish Science. Programme TEAM-TECH offers grants for research teams headed by leading scientists carrying out R&D projects related to a new product or production process (technological or manufacturing) of significant importance for the economy.
New concept of p-n tunnel junctions and their application in novel optoelectronic GaN-based devices will be investigated. Tunnel junctions may be applied to multicolor LEDs, vertical laser diodes, high power laser diode arrays, efficient solar cells or vertical n-p-n transistors. These devices will be fabricated using plasma assisted molecular beam epitaxy.
The project will involve collaboration between the Institute of High Pressure Physics Polis Academy of Sciences, Faculty of Physics Warsaw University, Faculty of Physics Wrocław University of Technology, Technical Universities of Madrid and Montpellier and TopGaN company, that develops commercial nitride laser diode solutions.
The innovative concept proposed in the project is based on the unique construction of the p-n tunnel junction that provides high tunneling efficiency through the junction minimizing its resistivity. The concept makes use of very high electric fields present in wurtzite crystal structure that modify the nitride tunnel junctions properties.
We will aim at fabrication edge-emitting laser diodes emitting at 480-490 nm (DFB – Distributed Feedback) and cascade multicolor LEDs. We will investigate the possibility of the application of tunnel junctions in monolithic vertical cavity surface emitting laser diodes (VCSELs).
Scientific results obtained in the Project will be commercialized in TopGaN company that will support the scientists in laser diodes and LEDs processing.
Research team of our TeamTECH project consists of experts in MBE, laser physics, modelling and laser processing:
Project is carried out in collaboration with:
Project is carried out from 2017 to 2019
Project results are published in:
Editors of renown journal publishing reports on newest development in applied physics- Applied Physics Express - highlited the paper about laser diodes with tunnel junction authored by MBE Group from UNIPRESS in collaboration with TopGaN. It is an appreciation that results reported in the paper are very interesting and worth sharing with larger amount of readers. Articles placed in the "Spotlights" section are available in OpenAccess.
Thanks to use of tunnel junction in LD's construction one can overcome techologically problematic p-type contact metallization. Moreover such a solution opens up new paths for constructing innovative devices such as cascade laser diodes or distributed feedback lasers. Click on the picture to access the paper.
We demonstrated a stack of two III-nitride laser diodes interconnected by a tunnel junction grown by plasma-assisted molecular beam epitaxy (PAMBE). The most important advantage of laser diode stacks is extremely high slope efficiency. We show the impact of the design of tunnel junction. In particular, we show that, apart from the beneficial piezoelectric polarization inside the TJ, heavy doping reduces the differential resistivity even further. The device starts to lase at a wavelength of 459 nm with a slope efficiency (SE) of 0.7 W/A followed by lasing at 456 nm from the second active region doubling the total SE to 1.4 W/A. This demonstration opens new possibilities for the fabrication of stacks of ultraviolet and visible high power pulsed III-nitride LD. Similar attractive possibility is the integration of multiple laser diodes emitting at the same wavelength in order to obtain ultra-high optical power.