Resistive gas sensors based on colloidal quantum dot (CQD) solids for hydrogen sulfide detection

Abstract Colloidal quantum dot (CQD) is emerging as new substitution gas sensing materials due to the excellent accessibility of gas molecules to CQD surfaces realized via surface ligand removal. Here we demonstrated highly sensitive and selective H2S gas sensors based on PbS CQD solids. The sensor resistance decreases upon H2S gas exposure and the response is defined as the ratio of the sensor resistance in clean air to that in H2S gas. As the operating temperature increased within the range 50–135 °C, the sensor response increased while the response and the recovery time decreased. The sensor was fully recoverable toward 50 ppm of H2S at 108 °C and the highest response was 2389 at 135 °C with the response and recovery time being 54 s and 237 s, respectively. The dependence of sensor response on the H2S gas concentration in the range of 10–50 ppm is linear, suggesting a theoretical detection limit of 17 ppb toward H2S at 135 °C. Meanwhile, the sensor showed superb response selectivity toward H2S against SO2, NO2 and NH3. We propose that the PbS CQDs film where the surface states determine the conduction type via remote doping may undergo a p-to-n transition due to H2S exposure at elevated temperatures.

[1]  William Mickelson,et al.  Low-power, fast, selective nanoparticle-based hydrogen sulfide gas sensor , 2012 .

[2]  R. Moradi,et al.  The correlation between the substrate temperature and morphological ZnO nanostructures for H2S gas sensors , 2014 .

[3]  Dongxiang Zhou,et al.  Nanocrystalline In2O3–SnO2 thick films for low-temperature hydrogen sulfide detection , 2011 .

[4]  R. Ruoff,et al.  All-organic vapor sensor using inkjet-printed reduced graphene oxide. , 2010, Angewandte Chemie.

[5]  Philippe Guyot-Sionnest,et al.  n-type colloidal semiconductor nanocrystals , 2000, Nature.

[6]  J. Luther,et al.  Stoichiometry control in quantum dots: a viable analog to impurity doping of bulk materials. , 2013, ACS nano.

[7]  Dongxiang Zhou,et al.  Properties and mechanism study of SnO2 nanocrystals for H2S thick-film sensors , 2009 .

[8]  Ari Kilpelä,et al.  A printed H2S sensor with electro-optical response , 2014 .

[9]  Dongxiang Zhou,et al.  Physically Flexible, Rapid‐Response Gas Sensor Based on Colloidal Quantum Dot Solids , 2014, Advanced materials.

[10]  V. Bulović,et al.  Control of the carrier type in InAs nanocrystal films by predeposition incorporation of Cd. , 2010, ACS nano.

[11]  Edward H. Sargent,et al.  Impact of dithiol treatment and air annealing on the conductivity, mobility, and hole density in PbS colloidal quantum dot solids , 2008 .

[12]  Kea-Tiong Tang,et al.  A review of sensor-based methods for monitoring hydrogen sulfide , 2012 .

[13]  Aram Amassian,et al.  Colloidal-quantum-dot photovoltaics using atomic-ligand passivation. , 2011, Nature materials.

[14]  Baoqing Zhang,et al.  Microstructure and enhanced H2S sensing properties of Pt-loaded WO3 thin films , 2014 .

[15]  Transduction in Semiconducting Metal Oxide Based Gas Sensors - Implications of the Conduction Mechanism , 2011 .

[16]  Photodetectors: A sensitive pair. , 2012, Nature nanotechnology.

[17]  Dongxiang Zhou,et al.  Tin oxide films for nitrogen dioxide gas detection at low temperatures , 2013 .

[18]  Edward H. Sargent,et al.  Engineering the temporal response of photoconductive photodetectors via selective introduction of surface trap states. , 2008, Nano letters.

[19]  V. Bulović,et al.  Emergence of colloidal quantum-dot light-emitting technologies , 2012, Nature Photonics.

[20]  O. Voznyy,et al.  N‐Type Colloidal‐Quantum‐Dot Solids for Photovoltaics , 2012, Advanced materials.