Two-Dimensional Nanocapacitors from Pristine and Hydrogenated Carbon Biphenylene Networks
Abstract
Two-dimensional nanocapacitors provide a promising route toward ultra-thin energy-storage devices, in which electrostatic screening and dielectric thickness play a central role. In this work, vertical metal–insulator–metal nanocapacitors based on carbon biphenylene networks are investigated using first-principles density functional theory. Pristine biphenylene is employed as the metallic electrode, while fully hydrogenated biphenylene serves as the dielectric layer, enabling a structurally compatible heterostructure. The electronic and electrostatic responses of C-BPN/CH-BPN/C-BPN nanocapacitors are examined for dielectric thicknesses ranging from one to five atomic layers. Under an applied vertical electric field, a clear and reversible charge separation develops across the metallic electrodes, while the dielectric layers remain essentially charge neutral, confirming polarization-dominated capacitive behavior. The excess charge scales linearly with the applied electric field, whereas the stored energy exhibits a quadratic dependence, consistent with classical electrostatics. The gravimetric capacitance shows a weak dependence on electric field strength and decreases systematically with increasing dielectric thickness. A maximum gravimetric capacitance of is obtained for the thinnest dielectric configuration. These results establish biphenylene-based heterostructures as a robust platform for nanoscale capacitive energy storage and demonstrate that device geometry provides an effective design space for optimizing capacitive performance in two-dimensional nanocapacitors.
Keywords
Density Functional Theory, Electrostatic Energy Storage, Gravimetric Capacitance, Nanocapacitors, Two-Dimensional Metal-Insulator-Metal Heterostructures
References
- [1] Conway, B. E. (1999). Electrochemical supercapacitors: Scientific fundamentals and technological applications. Springer. https://doi.org/10.1007/978-1-4757-3058-6
- [2] Miller, J. R., & Simon, P. (2008). Electrochemical capacitors for energy management. Science, 321(5889), 651–652. https://doi.org/10.1126/science.1158736
- [3] Simon, P., & Gogotsi, Y. (2008). Materials for electrochemical capacitors. Nature Materials, 7(11), 845–854. https://doi.org/10.1038/nmat2297
- [4] Geim, A. K., & Grigorieva, I. V. (2013). Van der Waals heterostructures. Nature, 499(7459), 419–425. https://doi.org/10.1038/nature12385
- [5] Dean, C. R., et al. (2010). Boron nitride substrates for high-quality graphene electronics. Nature Nanotechnology, 5(10), 722–726. https://doi.org/10.1038/nnano.2010.172
- [6] Ponomarenko, L. A., et al. (2010). Density of States and Zero Landau Level Probed through Capacitance of Graphene. Physical Review Letters, 105(13), 136801. https://doi.org/10.1103/PhysRevLett.105.136801
- [7] Kretinin, A. K., et al. (2013). Quantum capacitance measurements of electron-hole asymmetry and next-nearest-neighbor hopping in graphene. Physical Review B, 88(16), 165427. https://doi.org/10.1103/PhysRevB.88.165427
- [8] Shi, G., Hanlumyuang, Y., Liu, Z., Gong, Y., Gao, W., Li, B., Kono, J., Lou, J., Vajtai, R., Sharma, P., & Ajayan, P. M. (2014). Boron nitride–graphene nanocapacitor and the origins of anomalous size-dependent increase of capacitance. Nano Letters, 14(4), 1739–1744. https://doi.org/10.1021/nl4037824
- [9] Özçelik, V. O., & Ciraci, S. (2013). Nanoscale Dielectric Capacitors Composed of Graphene and Boron Nitride Layers: A First-Principles Study of High Capacitance at Nanoscale. The Journal of Physical Chemistry C, 117(29), 15327–15334. https://doi.org/10.1021/jp403706e
- [10] Özçelik, V. O., & Ciraci, S. (2015). High-performance planar nanoscale dielectric capacitors. Physical Review B, 91(19), 195445. https://doi.org/10.1103/PhysRevB.91.195445