Enhancing the AOTF-based NO2 camera with light polarization sensitivity for aerosol retrievals

The AOTF-based NO2 camera is a remote sensing instrument primarily aimed at imaging and quantifying the NO2 field above cities or in industrial plumes. The measurement principle consists in acquiring a number of spectral images of the scene at selected wavelengths. Each pixel is therefore recording a discrete spectrum of the radiance collected...

Performance of the AOTF-based NO2 camera for urban pollution imaging

An instrument capable of imaging the field of NO2 in various open-air situations has been designed, manufactured, and tested. It is an improved version of the NO2 camera relying on an AOTF (acousto-optical tunable filter) which has demonstrated, amongst other things, its capability to quantify the NO2 released by power plant smokestacks. The...

Investigation of multi-layered graphene/silicon Schottky junction in oxidizing atmosphere

In this study, we investigate a Schottky junction based on solution-processed multilayered graphene (MLG). We present a rectifying device obtained with a straightforward approach, that is drop-casting a few microliters of MLG solution simultaneously onto Si, Si-SiO2 and Si-SiO2-Cr/Au surface. Monitoring the modulation of Schottky barrier...

Analysis of a calibration method for non-stationary CVD multi-layered graphene-based gas sensors

Limitations such as lack of detected stationary signal and slow signal recovery after detection currently affect graphene-based chemi-sensors operating at room temperature. In this work, we model the behavior of a sensor in a test chamber having limited volume and simulating the environmental conditions. From this model, we mathematically derive...

Low Temperature CVD Grown Graphene for Highly Selective Gas Sensors Working under Ambient Conditions

In this paper we report on gas sensors based on graphene grown by Chemical Vapor Deposition at 850 °C. Mo was used as catalyst for graphene nucleation. Resistors were directly designed on pre-patterned Mo using the transfer-free process we recently developed, thus avoiding films damage during the transfer to the target substrate. Devices...

An innovative approach to overcome saturation and recovery issues of CVD graphene-based gas sensors

<br/>In this work, we present an innovative method which enables to solve fundamental limitations affecting graphene-based chemi-sensors operating under environmental conditions, namely the lack of signal saturation and the scarce recovery after the detection step. The method, which exploits the differential current instead of the current itself...

Air quality over the Canadian oil sands: A first assessment using satellite observations

Results from the first assessment of air quality over the Canadian oil sands–one of the largest industrial undertakings in human history–using satellite remote sensing observations of two pollutants, nitrogen dioxide (NO2) and sulfur dioxide (SO2), are presented. High-resolution maps were created that revealed distinct enhancements in both...