Wavelength tunable continuous wave metal halide perovskite lasers (PEROLAS)

• Applicants: Professor Dr. Ulrich Lemmer; Dr. Ulrich Wilhelm Paetzold
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering ; Experimental Condensed Matter Physics
• Term: from 2018 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 409035484

This proposal aims to realize solution-processable, continuous-wave (CW) optically-pumped lasers across the visible to the near infrared spectrum by developing lead-halide-based perovskite (LHP) optical gain materials and appropriately engineering device structures. Particular attention is given to tunability and to lasers in the green spectral range not adequately covered by current III-V semiconductor technology. We foresee future applications as integrated laser sources in sensing and metrology applications and in advanced display technologies, e.g. for virtual-reality (VR), and augmented-reality (AR) displays.This proposal presents a coordinated plan to optimize lasing in LHPs. The plan starts from the development of a deeper understanding of the physical processes limiting gain in LHPs, moves through an optimization of the materials aimed at alleviating the identified bottlenecks, and ends with the simulation, design and fabrication of lasers operating with distributed feedback resonators. The starting point for our physical understanding, material optimization, and device engineering work will be the triple cation and methylammonium LHP layers from which we have already reported lasing under pulsed excitation. The fundamental understanding of gain in LHPs that our proposal will generate, based on the comparative study of different LHP compositions (initially focusing on the different cations), is of significant relevance in light of the very recent report of CW lasing at 100 K from the single-cation methylammonium material. As of yet, the physical mechanisms that allow the material to lase at 100 K (with a mixed orthorhombic-tetragonal phase) but not at higher temperatures are unclear. Our starting comparative studies will establish the importance of fundamental physical processes (e.g, cation rotational freedom) in maintaining lasing under CW excitation and generate specific insight into how LHP materials should be developed to support CW lasing at higher temperatures. By combining expertise regarding material development, material characterization, and laser device design the project team has the breadth of experience to execute the proposed work.

• DFG Programme: Research Grants
• Co-Investigator: Ian Howard, Ph.D.