Search

Owing to the increasing demand for monitoring harmful toxic gases using small‐sized low‐power‐consumption gas sensors, a room‐temperature wireless complimentary gas sensor incorporating layered materials is proposed and demonstrated. The compact design allows the sensing module to be installed under all conditions and facilitates multiple detections of toxic gas. Highly chemical‐resistance‐sensitive materials based on n‐type SnSe2 and p‐type PtSe2 layered materials prepared by the plasma‐assisted chemical vapor reaction (PACVR) method at low temperatures are integrated with an oscillation circuit and antenna fabricated by a 28‐nm CMOS high‐k metal gate logic process to achieve dense, low‐powered, and wireless characteristics. By pairing n‐ and p‐type layered semiconductors, the gas sensors feature less influence from the surroundings, such as temperature and humidity, and enhance sensitivity to the target gas simultaneously. The wireless sensing detection method enables a sensor to make signal reception more convenient. Furthermore, a wireless gas sensor with self‐converging calibration using the advantage of a floating‐gate (FG) transistor to control the charge quantity by shifting the threshold voltage (Vth) of each transistor via the channel hot electron injection effect, which helps to reduce the impact of process variations, minimizing readout errors, is proposed. [ABSTRACT FROM AUTHOR]

A top‐down transfer process is developed via a rolling process associated with thermal release tape/poly(methyl methacrylate) (PMMA) bi‐supporting layers to realize large‐scale transfer processes on transition metal dichalcogenide materials. A 2‐inch MoS2 thin film transferred on SiO2/Si substrates with high integrity and a yield of ≈99% can be successfully achieved via the proposed process. MoS2‐based transistors with a transferred Au thin film as the contact electrode indicate a lower contact resistance of 8.4 kΩ with improved mobility and a higher on/off ratio compared with that of the MoS2‐based transistors with the evaporated Au thin film as the contact electrode. By applying the difference in adhesion force between metal oxides and metal on MoS2 and PMMA surfaces, the selective transfer of MoS2 films can be demonstrated. Furthermore, all‐transferred MoS2‐based transistor arrays are demonstrated by combining the selectively transferred MoS2 film as the channel material and the transferred Au thin films as the contact electrode, which results in uniform electrical properties featuring a carrier mobility of 10.45 cm2 V−1 s−1, a subthreshold swing of 203.94 mV dec−1, a normalized Ion of 8.3 μA μm−1, and an on/off ratio of 105. [ABSTRACT FROM AUTHOR]

The stability and robustness of lightly and highly doped poly-Si resistors were evaluated. These resistors exhibited distinct electrical resistance properties and temperature dependences, which can be explained through the grain and grain boundary conduction mechanisms. The resistance shift saturated under the low current stress condition, but continued to increase under the high current stress condition. A novel carrier trapping density model was proposed to explain this behavior. A generalized free energy model that considered stress temperature and stress current dependences was proposed to account for the stability lifetime of a poly-Si resistor based on the resistance shift criterion. Robustness evaluation with transmission line pulse test revealed that the breakdown current exhibited a pulse width dependence which was further explained by a thermal-conduction energy model. [ABSTRACT FROM AUTHOR]

A 2D SnSe2 layered film‐based gas detector incorporating a floating‐gate device coupled with metal interconnect wiring structures is proposed and demonstrated for the first time. Linear amplification can be readily implemented using a coupling ratio design, which refers to the capacitance ratio between the gate and device in the sense amplifier circuits. A sensitivity of 102 mV ppm−1 can be obtained using the 2D SnSe2 layered film with a thickness of 10 nm. The 2D SnSe2 layered film‐based complementary metal–oxide–semiconductor (CMOS) gas detector features highly sensitive, wide, and adjustable dynamic ranges with a real‐time response of the sub‐ppm detection limit on NO2 gas. In addition, the synthesis process of the SnSe2 layered film can occur at a low temperature and be operated at room temperature. Furthermore, 3 × 3 gas detector arrays with peripheral circuits demonstrate the functionality of multiple gas detection simultaneously and 16 × 16 arrays with a decoder and other peripheral circuits are constructed and simulated, providing the spatial distribution of the gas concentration in a specific region. The performance of the proposed detector is comparable to that of the other state‐of‐the‐art gas sensors. [ABSTRACT FROM AUTHOR]