Large area, inkjet printed and dual-coloured Perovskite-LEDs Vincent Schröder 1,2 , Nicolas Fratzscher 2 , Florian Mathies 3 , Edgar R. Nandayapa 3 , FelixHermerschmidt 2 , Eva L. Unger 3,4 and Emil J. W. List-Kratochvil 1,2 1 Helmholtz-Zentrum Berlin, Germany and 2 Humbolt-Universität zu Berlin, Germany 2 Humboldt-Universität zu Berlin, Institut für Physik, Institut für Chemie ,Berlin, Germany 3 Department Solution Processing of Hybrid Materials and Devices, Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany 4 Chemical Physics and NanoLund, Lund University, Sweden Metal halide perovskites (MHPs) are a semiconductor material used in solar cells, light emitting diodes, photodetectors and X-ray detectors. The deposition of MHPs from solution allows fast and energy-efficient fabrication of optoelectronic devices by high-throughput, large area coating technologies such as slot-die coating or inkjet printing. Beyond coating a large area, inkjet printing allows mixing of multiple inks and selective ink deposition in arbitrary patterns. However, the fabrication of high quality MHP layers, necessary for their implementation in optoelectronic devices, remains challenging on a larger scale. We demonstrate the successful upscaling of an inkjet printing process for the fabrication of MHP‑based light emitting diodes (PeLEDs) and selective structuring of the emitter layer to yield dual-colour light emission. Following the successful fabrication of green light emitting inkjet‑printed PeLEDs with a 4mm² active area and comparable performance to spin-coated reference devices, 1 we achieved a scale-up to 1600mm². By using a gas flow assisted vacuum drying (GAVD) method, 2 guiding a constant nitrogen gas stream over the 50 ×50mm substrate, homogeneous crystallization produced a high-quality MHP layer and large area PeLEDs without increasing leakage current. 3 Utilising the unique capabilities of inkjet printing, we then added a second printing step to the printing procedure to achieve dual-colour light emission: an iodide-based MHP composition is printed in an arbitrary pattern on the bromide-based MHP background layer. In a PeLED, the background layer emits green light (535nm) while the mixed halide MHPs in the printed pattern emits red light (710nm). The printed features have a minimum diameter of 100µm for a single printed dot and preserve the integrity of the primary MHP layer. The patterns show a strong visual contrast and form readable structures. 4 References 1. F. Hermerschmidt, F. Mathies, V. R. F. Schröder, C. Rehermann, N. Z. Morales, E. L. Unger and E. J. W. List-Kratochvil, Mater. Horizons , 2020, 7 , 1773–1781. 2. F. Mathies, E. R. Nandayapa, G. Paramasivam, M. F. Al Rayes, V. R. F. Schröder, C. Rehermann, E. J. W. List-Kratochvil and E. L. Unger, Mater. Adv. , 2021, 2 , 5365–5370. 3. V. R. F. Schröder, N. Fratzscher, F. Mathies, dgar R. Nandayapa, F. Hermerschmidt, va L. Unger and mil J. W. List- Kratochvil, Nanoscale , 2023, 15 , 5649–5654. 4. R. F. Schröder, N. Fratzscher, N. Z. Morales, D. S. Rühl, F. Hermerschmidt, E. L. Unger and E. J. W. List-Kratochvil, in preparation .
P31
© The Author(s), 2023
Made with FlippingBook Learn more on our blog