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arXiv · 2607.03428

Evidence of length scale effect in contact electrification in conducting thin film heterostructures

Paul C. Lou·Ravindra G. Bhardwaj·Anand Katailiha·W. P. Beyermann·Sandeep Kumar
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Abstract

Contact electrification between two conducting materials is expected to exhibit length scale effect because the screening effect will diminish in conductors as a function of material dimensions. As a consequence, the interfacial charge accumulation will diffuse away from interface/surface to a critical penetration depth as a function of material dimension. This work experimentally demonstrates the length scale effect in a permalloy and degenerately doped p-Si heterostructure system due to the flexoelectricity mediated contact electrification. The contact electrification induced interlayer charge transfer is observed through the whole thickness in case of 400 nm thick p-Si samples. Whereas, the charge carrier diffuses to a depth of 51 nm from the interface in case of 2 um thick Si. The length scale effect also leads to metal-insulator transition in p-Si layers in both cases. These results present a new opportunity to tailor the physical properties in conducting materials using contact electrification.

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Paul C. Lou, Ravindra G. Bhardwaj, Anand Katailiha, W. P. Beyermann, Sandeep Kumar. 2026-07-03. Evidence of length scale effect in contact electrification in conducting thin film heterostructures. https://arxiv.org/abs/2607.03428

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