New nano-composite based on carbon dots (CDots) decorated magnesium oxide (MgO) nano-particles (CDots@MgO) sensor for high H2S gas sensitivity performance

Schottky device based on carbon dots (C-Dots) decorated magnesium oxide (MgO) nano-particles ((MgO)-Mg-CDots@) has been engineered for H2S gas sensing applications. TEM microscope proves the decoration of C-Dots on the surface of MgO nano-particles. The sensor device has been tested for various reducing gases. However, (MgO)-Mg-CDots@ device displays high response against H2S gas, as a resultof reducing the barrier height between (MgO)-Mg-CDots@ crystals. I-V behavior of the engineered sensor device is examined under both open air and H2S gas environments. The parameters (series resistance R-s, effective barrier height phi(B), and ideality factor n) of the schottky diode are determined for the (MgO)-Mg-CDots@ and MgO based sensors. Interestingly, under the exposure of 120 ppm of H2S, (MgO)-Mg-CDots@ sensor has shown response current value 11 times higher than MgO sensor at external biasing voltage = -0.7 V. The reduction of barrier height can be observed with increasing the (T-applied) up to 200 degrees C and then increases. The obtained results prove that both device response and sensitivity are strongly influenced by the change in the barrier height. Finally, this effort introduces an invaluable methodology aiming at sensing the harmful gases by engineering a new gas sensor based on Schottky device of metal oxides decorated with C-Dots for high response, low power-consumption, high repeatability and high stability.

Automated summary

A Schottky device based on carbon dots decorated magnesium oxide nanoparticles has been engineered for H2S gas sensing applications, displaying high response and sensitivity due to reduced barrier height between crystals.