The synthesis, characterization, and application of two angular-shaped naphthalene bis(1,5-diamide-2,6-diylidene)malononitriles (NBAMs) as high-performance air-stable n-type organic field effect transistor (OFET) materials are reported. NBAM derivatives exhibit deep lowest-unoccupied molecular orbital (LUMO) levels, suitable for air-stable n-type OFETs. The OFET device based on NBAM-EH fabricated by vapor deposition exhibits a maximum electron mobility of 0.63 cm V s in air with an on/off current ratio ( I/ I) of 10.

Benzodipyrrole-2,6-dione-3,7-diylidenedimalononitriles (BDPMs) were synthesized as active materials for the use in air-stable n‑type organic field-effect transistors (OFETs), whose optical and electrochemical properties were examined. BDPM-based small molecules exhibit deep lowest unoccupied molecular orbital levels, which are required in air-stable n‑type OFETs. An OFET device that was based on BDPM-But and fabricated by vapor deposition provided a maximum electron mobility of 0.131 cm2 V–1 s–1 under ambient conditions.

In this study, the characteristics of ion-sensitive field-effect transistors (ISFETs) with silicon wire array channels and sensing membrane stacks of 3-aminopropyltriethoxysilane (APTES)/SiO2 were investigated. Si wires were fabricated by nanoimprint lithography and Si anisotropic/isotropic reactive-ion etching processes. The Si wires, with a line width of ~200 nm, were undercut and nearly suspended, which formed an Ω-shape cross-section. The aspects of wires were investigated using an optical microscope, an atomic force microscope, a scanning electron microscope, and a transmission electron microscope. The sensitivity, hysteresis, and drift of ISFETs were investigated. The above sensing properties were all significantly improved with the proposed channels and the sensing membrane stacks. As such, high-performance ISFETs can be realized for future biochemical applications.

This study demonstrated a polycrystalline-silicon (poly-Si)-based double-gate (DG) ion-sensitive field-effect transistors (DG-ISFETs) using APTES/SiO2 stack-sensing membrane. The APTES/SiO2 stack-sensing membrane enhanced the single-gate (SG) sensitivity, and suppressed the hysteresis. The DG structure was preferred to have a capacitive coupling effect and to amplify the sensitivity of ISFETs. The sensitivities of SG- and DG-ISFETs were approximately 56.8 and 294 mV/pH, respectively. In addition, the corresponding amplifying factor was approximately 5.2. With this approach, the poly-Si DG-ISFETs can be a candidate for future high-performance biochemical sensing applications.

This study demonstrated a polycrystalline-silicon (poly-Si)-based double-gate (DG) ion-sensitive field-effect transistors (DG-ISFETs) using APTES/SiO2 stack-sensing membrane. The APTES/SiO2 stack-sensing membrane enhanced the single-gate (SG) sensitivity, and suppressed the hysteresis. The DG structure was preferred to have a capacitive coupling effect and to amplify the sensitivity of ISFETs. The sensitivities of SG- and DG-ISFETs were approximately 56.8 and 294 mV/pH, respectively. In addition, the corresponding amplifying factor was approximately 5.2. With this approach, the poly-Si DG-ISFETs can be a candidate for future high-performance biochemical sensing applications.