Effect of the Deformation State on the Response of a Flexible H2S Sensor Based on a Ph5T2 Single-Crystal Transistor

Flexible H
₂
S sensors were fabricated based on ultrathin dinaphtho [3, 4-d:3', 4'-d'] benzo [1, 2-b:4, 5b'] dithiophene (Ph5T2) single-crystal organic field-effect transistors, and response performances at different deformation states were investigated. The flexible devices exhibited strikingly different sensing behaviors under different deformation states toward H
₂
S at room temperature. In a tensile state with r = 7 mm, the flexible sensor presented an unprecedented response as high as 400% at 1 ppm H
₂
S, which is almost one order of magnitude higher than the response in a flat state and surpasses all reported flexible H
₂
S sensors. Such a surprising improvement provides an effective way to enhance the response of gas sensors and shows the potential advantage of using flexible sensors in tensile states.