Modified Single Amino Acid‐Based Semiconductor: A Minimalistic Approach

Semiconductors are essential for the electronics industry, allowing the fabrication of transistors, diodes, integrated circuits, and other electronic devices. While inorganic semiconductors dominate the field due to their high performance and reliability, they pose challenges in biomedical applications due to low biocompatibility and limited morphological flexibility. Eco‐friendly organic semiconductors, which are easier to fabricate, are therefore extensively explored. Among these, self‐assembling peptide nanostructures with quantum confinement properties are gaining increasing attention. Despite limited reports on peptide‐based semiconductors, they hold great potential due to their low cytotoxicity and ability to generate currents in the nA range. Previous work demonstrated the conducting properties of cyclo‐Phe–Phe nanowires, showing a current of 1 nA at room temperature at 5 V, which increased to 2 nA at 387 K under the same voltage. Here, we present a phenylalanine‐based minimalistic building block that allows a current of 27 nA at room temperature at 2.5 V, the highest value reported so far for such a small molecule. Our findings reveal that the higher‐order of the crystal packing, facilitated by π – π stacking, plays a crucial role in its semiconducting properties, with π electronic systems significantly contributing to quantum confinement, which can be useful in various nanotechnology applications.