A 0.05 V driven ammonia gas sensor based on an organic diode with a top porous layered electrode and an air-stable sensing film

Abstract

In this work, we successfully demonstrated an extremely-low-voltage (0.05 V) gas sensor based on a vertical organic diode with work-function-matched electrodes.

Gate-tunable gas sensing behaviors in air-stable ambipolar organic thin-film transistors

“…3a, meaning that V TR shis are the results of the charge transfer between gas molecules and the sensing layer. 29,30 If the charge transfer is the only mechanism, g m which is extracted from the slope of the transfer curves should remain constant. However, it is also changing aer gas exposure as shown in Fig.…”

Solution-Processed Chloroaluminum Phthalocyanine (ClAlPc) Ammonia Gas Sensor with Vertical Organic Porous Diodes

“…Poly(3-hexylthiophene) (P3HT) solution (1.5 wt% in chlorobenzene) was spin coated (3500 rpm, 40 s) onto the PVP layer and annealed at 200 °C for 10 min as a surface modification layer to adsorb polystyrene (PS) nanospheres. PS nanospheres with a diameter of 200 nm were then coated for the following colloidal lithography process [ 18 , 19 , 20 , 21 ]. Aluminum 60 nm in thickness was thermally evaporated as the top electrode.…”

“…In order to investigate the gas sensing and electrical properties of the proposed ClAlPc VOD sensor, we utilized our standard sensor measurement system. More details of our sensing system have been reported in our prior works [ 19 , 21 ]. The target gas was introduced into a sensing chamber through a gas-tight syringe to interact with the sensor device.…”

“…In our prior works, we also successfully demonstrated numerous air-stable OSC gas sensors with room temperature operation for healthcare [ 14 , 15 , 16 ], environmental [ 17 , 18 , 19 ], and food quality monitoring [ 20 ]. In addition, we proposed an ultra-low power gas sensor based on a vertical organic diode (VOD) to detect ppb-level ammonia (NH 3 ) at room temperature [ 21 , 22 ]. The detection of NH 3 is very crucial because of its increasing utilization in multiple fields such as health and environmental monitoring, food quality testing, agricultural production, and industrial applications.…”

“…Apart from the advantages of MOS sensor arrays, there are still some challenges for developing a portable e-nose with MOS sensor arrays. For instance, most MOS sensor arrays require a high operating temperature, which consumes high energy and takes Sensors 2021, 21, 5783 2 of 9 extra time for heating before device operation [3]. To realize a reliable e-nose system, a lot of aspects including good sensitivity/selectivity, low power consumption, room temperature operation, high stability, compactness, and cost effectiveness should be considered [5].…”