Flexible Nanogenerators Based on Enhanced Flexoelectricity in Mn3O4 Membranes
2D materials; flexoelectric; oxide membrane
Atomically thin, few-layered membranes of oxides show unique physical and chemical properties compared to their bulk forms. Manganese oxide (Mn3O4) membranes are exfoliated from the naturally occurring mineral Hausmannite and used to make flexible, high-performance nanogenerators (NGs). An enhanced power density in the membrane NG is observed with the best-performing device showing a power density of 7.99mWm?2 compared to 1.04Wm?2 in bulk Mn3O4. A sensitivity of 108mVkPa?1 for applied forces <10N in the membrane NG is observed. The improved performance of these NGs is attributed to enhanced flexoelectric response in a few layers of Mn3O4. Using first-principles calculations, the flexoelectric coefficients of monolayer and bilayer Mn3O4 are found to be 50100 times larger than other 2D transition metal dichalcogenides (TMDCs). Using a model based on classical beam theory, an increasing activation of the bending mode with decreasing thickness of the oxide membranes is observed, which in turn leads to a large flexoelectric response. As a proof-of-concept, flexible NGs using exfoliated Mn3O4 membranes are made and used in self-powered paper-based devices. This research paves the way for the exploration of few-layered membranes of other centrosymmetric oxides for application as energy harvesters. 2023 Wiley-VCH GmbH.
Chowde Gowda C.; Cavin J.; Kumbhakar P.; Tiwary C.S.; Mishra R.
ISSN: 16136810; PubMed ID: 38152930; CODEN: SMALB
https://doi.org/10.1002/smll.202307167 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85180670361&doi=10.1002%2fsmll.202307167&partnerID=40&md5=4e0864f08a1af5e5ebd686a5552da9cb
Chowde Gowda C., School of Nano Science and Technology, Indian Institute of Technology, West Bengal, Kharagpur, 721302, India; Cavin J., Department of Physics, Washington University in St. Louis, St. Louis, 63130, MO, United States; Kumbhakar P., Metallurgical and Materials Engineering, Indian Institute of Technology, West Bengal, Kharagpur, 721302, India, Department of Physics and Electronics, Christ University, Karnataka, Bangalore, 560029, India; Tiwary C.S., School of Nano Science and Technology, Indian Institute of Technology, West Bengal, Kharagpur, 721302, India, Metallurgical and Materials Engineering, Indian Institute of Technology, West Bengal, Kharagpur, 721302, India; Mishra R., Department of Physics, Washington University in St. Louis, St. Louis, 63130, MO, United States, Department of Mechanical Engineering & Materials Science, and Institute of Materials Science & Engineering, Washington University in St. Louis, St. Louis, 63130, MO, United States