Electrolyte-gated organic transistors (EGOTs) are promising candidates as a new class of neuromorphic devices in hardware-based artificial neural networks that can outperform their complementary metal oxide semiconductor (CMOS) counterparts regarding processing speed and energy consumption. Several ways in which to implement such networks exist, two prominent methods of which can be implemented by nanoscopic vertical EGOTs, as we show here. First, nanoscopic vertical electrolyte-gated transistors with a donor−acceptor diketopyrrolopyrrole− terthiophene polymer as an active material can be used to reversibly switch the channel conductivity over five orders of magnitude (3.8 nS to 392 μS) and perform switching at low operation voltages down to −1 mV. Second, nanoscopic EGOTs can also mimic fundamental synaptic functions, and we show an interconnection of up to three transistors, highlighting the possibility to emulate biological nerve cells.

Metal-free organic perovskites such as [HMDABCO](NH 4 )I 3 ([HMDABCO 2+ ] = 1-methyl-1,4-diazabicyclo[2.2.2]octane-1,4-diium) have recently emerged as sustainable high-performance ferroelectrics. To realize their application as a substitute for metal-based analogues in microelectronic devices, it is mandatory to establish a process for their fabrication in the form of thin films. Here, we investigate different deposition techniques such as spin, spray, and drop coating for their eligibility in the production of crystalline, dense, and smooth [HMDABCO](NH 4 )I 3 thin films. By systematically varying different process parameters, we show how to control the thin-film thickness, influence the preferred crystallite orientation, and obtain dense thin films, which were characterized by grazing incidence X-ray diffraction, scanning electron microscopy, and atomic force microscopy. Our work presents the first deposition of [HMDABCO](NH 4 )I 3 as thin films and provides the experimental and scientific basis for further systematic investigations.