Silicon-based long-wave infrared detectors for flammable gas sensing
Journal
Journal of Hazardous Materials
Journal Volume
507
Start Page
141629
ISSN
03043894
Date Issued
2026-04-01
Author(s)
Abstract
Given the current industrial development trends, flammable gases are becoming increasingly important. However, the hazards associated with the storage and transportation of flammable gases pose risks to property and human life. Hence, there is an urgent need to develop gas sensors capable of instantaneous detection and operation at room temperature. In this study, we fabricated the first room-temperature silicon (Si)-based optical detectors for propylene (C3H6) and methane (CH4), which have been reported to cause numerous deaths. The characteristic fingerprint absorption bands of C3H6 and CH4 within the long-wave infrared (LWIR) region were used for gas sensing with hot-carrier-type Si-based photodetectors. Operating at room temperature and featuring a short response time of less than 1 ms, these sensors significantly reduced the risk of potential explosion hazards and enabled real-time detection. Detection of the asymmetric bending vibration at 7.8 μm provided more selectivity than that of the symmetric stretching vibration at 3.3 μm for carbon-hydrogen bonds in CH4, enabling a clear distinction between flammable gases, such as CH4 and C3H6. Additionally, the sensor demonstrated a limit of detection (LOD) for C3H6 and CH4 well below their respective explosion threshold. The combination of a short response time and low LOD confirms the capability of the sensor to provide an early warning of gas leakage.
Subjects
Flammable gas sensing
Long-wave infrared (LWIR) detector
Methane (CH4)
Optical-based gas sensor
Propylene (C3H6)
Real-time detection
Si-based sensor
Publisher
Elsevier B.V.
Type
journal article