Metal–Insulator–Insulator–Metal (MIIM) Ag/SnO2/Al2O3/Ag Diodes Fabricated by Ultraprecise Dispensing and Atomic Layer Deposition

Publication Type

Journal Article

Name of Author

• Aboubacar Savadogo, Department of Physics, University of Nairobi, Nairobi, KenyaFollow
• Klaus Huska, Light Technology Institute (LTI), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
• Rohit D. Chavan, Light Technology Institute (LTI), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
• Thomas Nyachoti Nyangonda, Department of Physics, University of Nairobi, Nairobi, Kenya
• Jan Feßler, Light Technology Institute (LTI), Karlsruhe Institute of Technology (KIT), Karlsruhe, German
• Bernard Odhiambo Aduda, Department of Physics, University of Nairobi, Nairobi, Kenya
• Ulrich Wilhelm Paetzold, Light Technology Institute (LTI), Karlsruhe Institute of Technology (KIT), Karlsruhe, German
• Uli Lemmer, Light Technology Institute (LTI), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
• Mohamed Hussein, Light Technology Institute (LTI), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

Publication Date (Issue Year)

2026

Journal Name

Advanced Electronic Materials

Abstract

Currently, high-frequency, ultra-fast, and tunneling diodes are mainly fabricated using traditional lithography and evaporation techniques, typically limited to wafer sizes. This work introduces a new method for fabricating metal–insulator–insulator– metal (MIIM) diodes using ultra-precise dispensing (UPD) printing techniques, providing a practical alternative to traditional lithography. Enabling highly precise material deposition, minimizing waste and boosting manufacturing efficiency. Both bottom and top electrodes of the MIIM diode are silver(Ag) and fabricated via UPD, while atomic layer deposition (ALD) is employed to deposit the insulating layers. 1 nm of tin oxide(SnO2) and 1 nm of aluminum oxide(Al2O3) sandwiched between the electrodes: The Ag/SnO2/Al2O3/Ag MIIM diode has a contact area of ca. 5.4 µm × 4.0 µm determined by FIB-SEM. A quantum simulator based on the Wentzel-Kramers-Brillouin (WKB) method is used to analyze the diode’s performance and shows agreement with measurement results. The electrical characterization of the fabricated MIIM device exhibits a tunneling current in the nano- to microampere range, a zero-bias responsivity of −1.31 A/W, and dynamic resistance of 39.56 kΩ. Combining ultra-precise printing with innovative insulators provides a promising pathway to large-scale, low-cost production of high-performance MIM diodes for energy harvesting, high-frequency rectification, and flexible applications electronics.

Keywords

metal insulator insulator metal (MIIM), diode, rectenna, responsivity, ultra-precise dispensing, wentzel-kramers-brillouin (WKB)

Rsif Scholar Name

Aboubacar Savadogo

Rsif Scholar Nationality

Burkina Faso

Cohort

Cohort 3

Thematic Area

Energy including Renewables

Africa Host University (AHU)

University of Nairobi (UoN), Kenya

Funding Statement

This work was supported by the Partnership for Skills in AppliedSciences, Engineering and Technology (PASET)- Regional Scholarshipand Innovation Fund (RSIF)

Recommended Citation

Savadogo, A., Huska, K., Chavan, R. D., Nyangonda, T. N., Feßler, J., Aduda, B. O., Paetzold, U. W., Lemmer, U., & Hussein, M. (2026). Metal–Insulator–Insulator–Metal (MIIM) Ag/SnO2/Al2O3/Ag Diodes Fabricated by Ultraprecise Dispensing and Atomic Layer Deposition. Advanced Electronic Materials https://doi.org/doi.org/10.1002/aelm.202500615