Charge Reservoirs in an Expanded Halide Perovskite Analog: Enhancing High‐Pressure Conductivity through Redox‐Active Molecules

Journal Article · 03 May 2022 · Angewandte Chemie

DOI: https://doi.org/10.1002/ange.202202911 · OSTI ID:1866296

Matheu, Roc  ^[1]; Ke, Feng ^[2]; Breidenbach, Aaron ^[3]; Wolf, Nathan R. ^[1]; Lee, Young ^[4]; Liu, Zhenxian ^[5]; Leppert, Linn ^[6]; Lin, Yu ^[7]; Karunadasa, Hemamala I.  ^[8]

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1. Department of Chemistry Stanford University Stanford CA 94305 USA
2. Stanford Institute for Materials and Energy Sciences SLAC National Accelerator Laboratory Menlo Park CA 94025 USA, Department of Geological Sciences Stanford University Stanford CA 94305 USA
3. Stanford Institute for Materials and Energy Sciences SLAC National Accelerator Laboratory Menlo Park CA 94025 USA, Department of Physics Stanford University Stanford CA 94305 USA
4. Stanford Institute for Materials and Energy Sciences SLAC National Accelerator Laboratory Menlo Park CA 94025 USA, Department of Applied Physics Stanford University Stanford CA 94305 USA
5. Department of Physics University of Illinois at Chicago Chicago IL 60607 USA
6. MESA+ Institute for Nanotechnology University of Twente 7500 AE Enschede The Netherlands
7. Stanford Institute for Materials and Energy Sciences SLAC National Accelerator Laboratory Menlo Park CA 94025 USA
8. Department of Chemistry Stanford University Stanford CA 94305 USA, Stanford Institute for Materials and Energy Sciences SLAC National Accelerator Laboratory Menlo Park CA 94025 USA

Abstract As halide perovskites and their derivatives are being developed for numerous optoelectronic applications, controlling their electronic doping remains a fundamental challenge. Herein, we describe a novel strategy of using redox‐active organic molecules as stoichiometric electron acceptors. The cavities in the new expanded perovskite analogs (dmpz)[Sn ₂ X ₆ ], (X=Br ⁻ ( 1Br ) and I ⁻ ( 1I )) are occupied by dmpz ²⁺ ( N , N ′‐dimethylpyrazinium), with the LUMOs lying ca. 1 eV above the valence band maximum (VBM). Compressing the metal‐halide framework drives up the VBM in 1I relative to the dmpz LUMO. The electronic conductivity increases by a factor of 10 ⁵ with pressure, reaching 50(17) S cm ⁻¹ at 60 GPa, exceeding the high‐pressure conductivities of most halide perovskites. This conductivity enhancement is attributed to an increased hole density created by dmpz ²⁺ reduction. This work elevates the role of organic cations in 3D metal‐halides, from templating the structure to serving as charge reservoirs for tuning the carrier concentration.

• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1866296
• Journal Information: Angewandte Chemie, Journal Name: Angewandte Chemie Journal Issue: 25 Vol. 134; ISSN 0044-8249
• Publisher: Wiley Blackwell (John Wiley & Sons)Copyright Statement
• Country of Publication: Germany
• Language: English