Lithographically Patterning Hybrid Perovskite Single Crystals by Surface-Engineered Amino-Deliquescence/Efflorescence

• Published in: ACS photonics 2021-08, Vol.8 (8), p.2329-2336
• Main Authors: Meyers, Jonathan K, Serafin, Lorenzo Y, Orr, Andre D, McKinney, Collin J, Cahoon, James F
• Format: Article
• Language: English
• ISSN: 2330-4022; 2330-4022
• DOI: 10.1021/acsphotonics.1c00495

Motivated by the extraordinary physical properties and potential optoelectronic applications of organic–inorganic hybrid perovskites (HPs), a variety of methods to synthesize and design high-quality HP structures has been developed. Nevertheless, the soft, organic nature of HP materials such as methylammonium lead iodide (MAPbI3) poses limitations to existing techniques, particularly for patterning the materials. Here, we demonstrate a hybrid top-down/bottom-up approach to patterning single-crystal HP microstructures. First, top-down lithography and chemical surface functionalization are used to prepare patterns with specific surface characteristics. Next, solid MAPbI3 powder is deposited on the patterns and liquefied by amino-deliquescence with methylamine (MA0) vapor, causing liquid MA0(MAPbI3) n to flow into the patterns while dewetting the remaining substrate. Lastly, MAPbI3 recrystallizes in the patterns by amino-efflorescence. By controlling the nucleation and growth conditions during amino-efflorescence, the characteristic grain size during recrystallization is orders of magnitude larger than the feature sizes of the patterns, thus causing the patterned microstructures to be single crystals. Contact angle measurements between liquid MA0(MAPbI3) n and a variety of organic and inorganic surfaces with and without chemical functionalization show that the wettability of surfaces can be tuned over a large range, providing flexibility in the choice of substrate and lithographic resist. The microstructures are free of exogenous solvents and suitable for optoelectronic device integration. As proof of concept, we demonstrate a photodetector that exhibits performance metrics consistent with single-crystal MAPbI3. The results provide a process for photonic and optoelectronic device design that can likely be extended to other potentially amino-deliquescent HP materials.