Fabrication and characterization of Cu₂S-based gas microsensors with sensitivity to NO₂

Abstract

Copper sulfide (Cu2S) thin films are synthesized via aerosol-assisted chemical vapor deposition (AACVD) of [Cu(Et<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf>P<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>)Cl]<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> complex. These films are directly integrated on silicon-based micromachined substrates and are tested as gas sensing materials. Results demonstrate the AACVD of crystalline flake-like Cu<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>S structures, while surface analysis indicate the presence of other copper species, including CuS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and metal sulfides. The integrated microsensors reveal selective response to nitrogen dioxide (NO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">₂</inf>) detection under photoactivation at room temperature.