Green Manufacturing of Nanoscale Devices
SEM and TEM images are published in https://doi.org/10.1038/s41528-018-0031-3
Fabrication of nanogap electrodes, namely coplanar metal structures separated by a nanogap of around 10-20nm, is traditionally challenging. It requires costly and time- and energy-consuming techniques, such as electron-beam lithography. On the other hand, these nanostructures are offering many advantages to the realisation of devices and circuit elements with lower power consumption, faster operating speed, and higher-level integration.
In the Flexible Nanoelectronics Lab we use these structures as our testbed to investigate the fundamental properties of materials at the nano- or even molecular level. We employ adhesion lithography (a-lith), a facile, inexpensive, high-throughput patterning technology to create our nanogap electrodes. We employ different metal combinations (M1 and M2 in scheme below), different shapes and aspect ratios (square, circular, interdigitated, spiral…) and rigid (Si/SiO2, glass) or flexible substrates (PET, PI) depending on the application.
We combine these coplanar nanogap electrodes with advanced functional materials (metal oxides, polyoxometalates, perovskites, 2D transition metal dichalcogenides, organic semicondunctors, ferroelectric polymers, quantum dots, etc.) to demonstrate high performance in devices, such as radiofrequency diodes, photodetectors, memristive devices, molecular memories and sensors. See below for some relevant articles published using a-lith fabricated nanogap electrodes.
-
1) Few-femtosecond soft X-ray transient absorption spectroscopy with tuneable DUV-Vis pump pulses. Lee J. P., Avni T., Alexander O., Maimaris M., Ning H., Bakulin A. A., Burden P. G., Moutoulas E., Georgiadou D. G., Brahms C., Travers J. C., Marangos J. P., and Ferchaud C. Optica 11, 1320-1323, https://doi.org/10.1364/OPTICA.530964 (2024).
2) High On/Off Ratio Carbon Quantum Dot–Chitosan Biomemristors with Coplanar Nanogap Electrodes. Raeis-Hosseini, N., Georgiadou, D. G. & Papavassiliou, C. ACS Applied Electronic Materials 5, 138-145, https://doi.org/10.1021/acsaelm.2c00979 (2023).
3) Towards Solution-Processed RF Rectennas: Experimental Characterization and Non-Linear Modelling based on ZnO Nanogap Diodes. Wagih, M. & Georgiadou, D. G. in 2022 29th IEEE International Conference on Electronics, Circuits and Systems (ICECS) 1-4.
4) Rapid and up-scalable manufacturing of gigahertz nanogap diodes. Loganathan, K., Faber, H., Yengel, E., Seitkhan, A., Bakytbekov, A., Yarali, E., Adilbekova, B., Al Batati, A., Lin, Y., Felemban, Z., Yang, S., Li, W., Georgiadou, D. G., Shamim, A., Lidorikis, E. & Anthopoulos, T. D. Nature Communications 13, 3260, https://doi.org/10.1038/s41467-022-30876-6 (2022).
5) Radiofrequency Schottky Diodes Based on p-Doped Copper(I) Thiocyanate (CuSCN). Georgiadou, D. G., Wijeyasinghe, N., Solomeshch, O., Tessler, N. & Anthopoulos, T. D. ACS Applied Materials & Interfaces 14, 29993-29999, https://doi.org/10.1021/acsami.1c22856 (2022).
6) Colossal Tunneling Electroresistance in Co-Planar Polymer Ferroelectric Tunnel Junctions. Kumar, M., Georgiadou, D. G., Seitkhan, A., Loganathan, K., Yengel, E., Faber, H., Naphade, D., Basu, A., Anthopoulos, T. D. & Asadi, K. Advanced Electronic Materials 6, 1901091, https://doi.org/https://doi.org/10.1002/aelm.201901091 (2020).
7) 100 GHz zinc oxide Schottky diodes processed from solution on a wafer scale. Georgiadou, D. G., Semple, J., Sagade, A. A., Forstén, H., Rantakari, P., Lin, Y.-H., Alkhalil, F., Seitkhan, A., Loganathan, K., Faber, H. & Anthopoulos, T. D. Nature Electronics 3, 718-725, https://doi.org/10.1038/s41928-020-00484-7 (2020).
8) High Responsivity and Response Speed Single-Layer Mixed-Cation Lead Mixed-Halide Perovskite Photodetectors Based on Nanogap Electrodes Manufactured on Large-Area Rigid and Flexible Substrates. Georgiadou, D. G., Lin, Y.-H., Lim, J., Ratnasingham, S., McLachlan, M. A., Snaith, H. J. & Anthopoulos, T. D. Advanced Functional Materials 1901371, https://doi.org/10.1002/adfm.201901371 (2019).
9) Flexible nanogap polymer light-emitting diodes fabricated via adhesion lithography (a-Lith). Wyatt-Moon, G., Georgiadou, D. G., Zoladek-Lemanczyk, A., Castro, F. A. & Anthopoulos, T. D. Journal of Physics: Materials 1, 01LT01, https://doi.org/https://doi.org/10.1088/2515-7639/aadd57 (2018).
10) Large-area plastic nanogap electronics enabled by adhesion lithography. Semple, J., Georgiadou, D. G., Wyatt-Moon, G., Yoon, M., Seitkhan, A., Yengel, E., Rossbauer, S., Bottacchi, F., McLachlan, M. A., Bradley, D. D. C. & Anthopoulos, T. D. npj Flexible Electronics 2, 18, https://doi.org/10.1038/s41528-018-0031-3 (2018).
11) Deep Ultraviolet Copper(I) Thiocyanate (CuSCN) Photodetectors Based on Coplanar Nanogap Electrodes Fabricated via Adhesion Lithography. Wyatt-Moon, G., Georgiadou, D. G., Semple, J. & Anthopoulos, T. D. ACS Applied Materials & Interfaces 9, 41965-41972, https://doi.org/10.1021/acsami.7b12942 (2017).
12) Semiconductor-Free Nonvolatile Resistive Switching Memory Devices Based on Metal Nanogaps Fabricated on Flexible Substrates via Adhesion Lithography. Semple, J., Wyatt-Moon, G., Georgiadou, D. G., McLachlan, M. A. & Anthopoulos, T. D. IEEE Transactions on Electron Devices 64, 1973-1980, https://doi.org/10.1109/ted.2016.2638499 (2017).
13) Adhesion lithography for fabrication of printed radio-frequency diodes. Georgiadou, D. G., Semple, J. & Anthopoulos, T. D. SPIE Newsroom, https://doi.org/10.1117/2.1201611.006783 (2017).
