Inorganic Perovskite Quantum Dot-Based Strain Sensors for Data Storage and In-Sensor Computing

TLDR

Stretchable strain sensors have improved, yet challenges remain in intelligent sensing, simultaneous data processing, and scalable fabrication. This study presents a strain‑sensitive device by fabricating a CsPbBr₃ quantum‑dot floating‑gate FET sensing array on thin polyimide films. The device uses CsPbBr₃ QDs as a trapping layer in a floating‑gate FET, enabling UV‑induced photogenerated carriers that markedly increase the source–drain current. The FET achieves an on/off ratio >10³, a memory window >2 V, strain‑dependent IDS over +12.5 % compressive to –10.8 % tensile, excellent data retention and durability, and emulates synaptic LTP/LTD functions, demonstrating multifunctional intelligent sensing potential.

Abstract

Although remarkable improvement has been achieved in stretchable strain sensors, challenges still exist in aspects including intelligent sensing, simultaneous data processing, and scalable fabrication techniques. In this work, a strain-sensitive device is presented by fabricating a CsPbBr3 quantum dots (QDs) floating-gate field-effect transistor (FET) sensing array on thin polyimide (PI) films. The FET exhibits an excellent on/off ratio (>103) and a large memory window (>2 V). With the introduction of CsPbBr3 QDs as the trapping layer, an additional UV response is obtained because of the photogenerated charge carriers that significantly enhance the source–drain current (IDS) of the device. At each electrical state, the IDS varies with the strains and the sensing range is from compressive +12.5% to tensile −10.8%. Excellent data retainability and mechanical durability demonstrate the high quality and reliability of the fabricated sensors. Furthermore, synapse functions including long-term potentiation (LTP), long-term depression (LTD), etc., are emulated at the device level. Linearity factor changes of LTP/LTD in different sensing scenarios demonstrate the reliability of the device and further confirm the different sensing mechanisms with/without UV illumination. Our results exhibit the potential of transistor-based devices for multifunctional intelligent sensing.