Electrical Sensing of Molecular Spin State Switching in a Spin Crossover Complex Using an Organic Field‐Effect Transistor

• Published in: Advanced Electronic Materials
• Main Authors: Yuteng Zhang, Seyed Ehsan Alavi, Ion Soroceanu, Dennis Wanyoike Kamau, Aurelian Rotaru, Isabelle Séguy, Lionel Salmon, Gábor Molnár, Azzedine Bousseksou
• Format: Article
• Language: English
• Published: Wiley-VCH 2025-04-01
• Subjects: mechanical strain; organic semiconductor; spin crossover; transistor
• Online Access: https://doi.org/10.1002/aelm.202400590

Abstract An organic semiconductor – spin crossover polymer composite heterostructure is fabricated, and it is integrated into an organic field‐effect transistor (OFET) with the aim to achieve electrical sensing of molecular spin state switching events. The OFETs display ≈50–70% increase in drain‐source current intensity when going from the low spin (LS) to the high spin (HS) state. This phenomenon is reversible without apparent fatigue and the application of a gate voltage significantly enhances the sensing sensitivity. Capacitance measurements and finite element calculations allow identifying mechanical stress, induced by the spin state switching, at the origin of the transistor response. These results open up appealing perspectives for the integration of spin crossover molecules into technological applications, such as soft robotics .