Ions in Electronic Devices – ECRAM and Perovskite Solar Cells

Abstract:

For more than a few decades, semiconductor devices and electrochemical devices have been completely separated fields with seemingly no interrelation between the two. Electrochemical devices would typically be based on ionic solutions. In contrast, semiconductor devices would be based on a solid state where the charge carriers are electrons and holes (no ions, please). Over the years, the two communities developed different scientific languages that enhanced the separation between the two. However, the fields share the primary chemical or physical concepts, and in recent years we have seen an increased intermixing between the two.

Such intermixing can be found in the newly introduced microelectronic device, the electrochemical random access memory (ECRAM). In the green-energy field, we find perovskite solar cells. In the first, the primary function relies on mobile ions, while in the second, the ions being mobile is linked to the room-temperature crystallisation and the resulting optoelectronic properties.

In my talk, I will introduce the two devices and present insights from 2D semiconductor device model that incorporates (part of the) electrochemistry. In both cases, I’ll show that the model was validated with the aid of results obtained by our collaborators. As a teaser, I would say that in the context of ECRAM, plating is not reserved for batteries and doping is not the best way to activate the channel. For the perovskite solar cells, I would suggest that the degradation of high-quality devices is due to the blocking layers, not the perovskite material itself.

Nir Tessler

Sara and Moshes Zisapel Nano-electronic center, Electrical and Computer Engineering, Technion Israel Institute of Technology, Haifa, Israel