Room-Temperature Semiconductor Gas Sensors: Challenges and Opportunities

Abstract

Our demand for ubiquitous and reliable gas detection is spurring the design of intelligent and enabling gas sensors for the next-generation Internet of Things and Artificial Intelligence. The desire to introduce gas sensors everywhere is fueled by opportunities to create room-temperature semiconductor gas sensors with ultralow power consumption. In this Perspective, we provide an overview of the recent achievement of room-temperature gas sensors that have been translated from the advances in the design of the chemical and physical properties of low-dimensional semiconductor nanomaterials. The emergence of solutionprocessable nanomaterials opens up remarkable opportunities to integrate into highperformance and flexible room-temperature gas sensors by using low-temperature, large-area, solution-based methods instead of costly, high-vacuum, high-temperature device manufacturing processes. We review the fundamental factors which affect the receptor and transducer functions of semiconductor gas sensors. We also discuss challenges that must be addressed in the move to the continuous miniaturization and evolution of semiconductor gas sensors.

Review and Perspective: Gas Separation and Discrimination Technologies for Current Gas Sensors in Environmental Applications

“…Both POMs and CQDs can be designed to detect a targeted gas, including VOCs, nitrogen oxides, and carbon monoxide, with high sensitivity and selectivity. Their applications have been reviewed by Tang et al and Song et al, respectively.…”

Deciphering Alloy Composition in Superconducting Single-Layer FeSe1–xSx on SrTiO3(001) Substrates by Machine Learning of STM/S Data

“…Chemical doping is often exploited to tune material properties. − For example, in semiconductors, aliovalent substitution leads to p- and n-type doping, the key elements of devices such as diodes and transistors that enable applications in modern electronics such as information processing, sensing, energy harvesting, and medical devices. − Though a critical component, such substitutions can also introduce chemical and electronic inhomogeneities at the nanoscale, which can significantly impact the carrier mobility and performance of semiconducting devices. These inhomogeneities can be particularly detrimental with shrinking device dimensions, including the recent emergence of two-dimensional semiconducting monolayered materials. − On the other hand, for quantum materials, these heterogeneities are usually correlated and give rise to quantum phenomena such as entanglement and topological effects, magnetism, and superconductivity. − , For instance, vacancy defects in wide bandgap semiconductors, such as diamond and silicon carbide, can result in tightly bound and robust spin states even at room temperature.…”

Direct Active Site at the Van der Waals Heterostructure Interface with Synthetic Drug Analogue N-Methylphenethylimine Ultrasensitivity

“…Low-dimensional VDW heterostructures, such as the well-known carbon nanotube (CNT) composites, have been widely utilized for nanophotonic biosensing, electronic devices, and strain sensor. − As for room-temperature sensing, the large specific surface area, stable aggregated morphological structure, good conductivity, and small humidity response of carbon nanotubes can be used to prepare ultrasensitive sensing materials for vapor-sensing applications. The sensing performance can be further enhanced due to the higher structural design flexibility and the molecule-scale accuracy of host–guest interaction, compared with conventional semiconductor sensors , and QCM gas sensors. , However, the construction of a stable contact at the CNT/sensory material molecule VDW interface still remains a big challenge, which greatly limits the precision, sensitivity, and selectivity of sensory systems. The vapor adsorption ability of carbon nanotubes without sensory molecules is quite limited; hence, a variety of materials, from noble metals, metal oxides, organic small molecules to polymers, have been utilized for chemical sensing to improve the sensitivity and selectivity. − However, upon chemical modification, the conductivity of CNT would be reduced due to the breakage of the π-conjugation system of CNT.…”

“…3−5 As for roomtemperature sensing, the large specific surface area, stable aggregated morphological structure, good conductivity, and small humidity response of carbon nanotubes can be used to prepare ultrasensitive sensing materials for vapor-sensing applications. The sensing performance can be further enhanced due to the higher structural design flexibility and the moleculescale accuracy of host−guest interaction, compared with conventional semiconductor sensors 6,7 and QCM gas sensors. 8,9 However, the construction of a stable contact at the CNT/sensory material molecule VDW interface still remains a big challenge, which greatly limits the precision, sensitivity, and selectivity of sensory systems.…”