Confining metal-halide perovskites in nanoporous thin films

• Published in: Science advances Vol. 3; no. 8; p. e1700738
• Main Authors: Demchyshyn, Stepan, Roemer, Janina Melanie, Groiß, Heiko, Heilbrunner, Herwig, Ulbricht, Christoph, Apaydin, Dogukan, Böhm, Anton, Rütt, Uta, Bertram, Florian, Hesser, Günter, Scharber, Markus Clark, Sariciftci, Niyazi Serdar, Nickel, Bert, Bauer, Siegfried, Głowacki, Eric Daniel, Kaltenbrunner, Martin
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 01.08.2017
• Subjects: Materials Science; SciAdv r-articles
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.1700738

Controlling the size and shape of semiconducting nanocrystals advances nanoelectronics and photonics. Quantum-confined, inexpensive, solution-derived metal halide perovskites offer narrowband, color-pure emitters as integral parts of next-generation displays and optoelectronic devices. We use nanoporous silicon and alumina thin films as templates for the growth of perovskite nanocrystallites directly within device-relevant architectures without the use of colloidal stabilization. We find significantly blue-shifted photoluminescence emission by reducing the pore size; normally infrared-emitting materials become visibly red, and green-emitting materials become cyan and blue. Confining perovskite nanocrystals within porous oxide thin films drastically increases photoluminescence stability because the templates auspiciously serve as encapsulation. We quantify the template-induced size of the perovskite crystals in nanoporous silicon with microfocus high-energy x-ray depth profiling in transmission geometry, verifying the growth of perovskite nanocrystals throughout the entire thickness of the nanoporous films. Low-voltage electroluminescent diodes with narrow, blue-shifted emission fabricated from nanocrystalline perovskites grown in embedded nanoporous alumina thin films substantiate our general concept for next-generation photonic devices.