Flexible narrowband photodetectors based on solution-processed 2D perovskites

• Applicant: Professorin Dr. Franziska Muckel
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 557602081

Flexible narrowband photodetectors enable applications such as computer vision on curved surfaces or medical sensors. This project aims to develop flexible, narrowband photodetectors for monocromatic optoelectronic systems that enhance information acquisition by reducing background interference and improving the signal-to-noise ratio. The focus is on achieving detectors with a bandwidth of <30 nm and response times significantly smaller than 1 ms, requirements unmet by current organic semiconductor approaches. As core innovation 2D perovskites will be used as narrowband absorbers in photodetectors to create color-selective, fast, and flexible components. Due to their 2D structure, perovskites exhibit strong absorption resonances with a spectral bandwidth below 30 nm that can be tuned across the visible spectrum by tailoring the material. The use of these absorbers enables response times below 200 micro seconds, offering significant potential for novel sensors in flexible electronics. Within the project photodetectors for the green spectral range will be developed using iodide perovskites with quantum well thicknesses of one unit cell. To optimize performance, organic interlayers are modified to increase lattice stiffness, reducing electron-phonon coupling and minimizing non-radiative losses. Despite the high exciton binding energy, the photodetectors demonstrate efficient charge carrier separation. The project seeks to uncover the mechanisms behind this and explore the introduction of a vertical type II heterojunction in the active layer to further enhance charge separation. Based on the gained knowledge photodetectors for the red and blue spectral ranges will be developed by adjusting the quantum well thickness and replacing halogens. A key challenge is achieving phase-pure iodide and bromide perovskites with two-unit-cell quantum wells. The ultimate goal is to create photodetectors with <30 nm bandwidth, <200 micro seconds response times, and high double-digit external efficiency across all spectral ranges.

• DFG Programme: Research Grants