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 (CDots) decorated magnesium oxide (MgO) nano-particles ([email protected]MgO) has been engineered for H2S gas sensing applications. TEM microscope proves the decoration of CDots on the surface of MgO nano-particles. The sensor device has been tested for various reducing gases. However, [email protected]MgO device displays high response against H2S gas, as a resultof reducing the barrier height between [email protected]MgO crystals. I–V behavior of the engineered sensor device is examined under both open air and H2S gas environments. The parameters (series resistance Rs, effective barrier height ϕB, and ideality factor n) of the schottky diode are determined for the [email protected]MgO and MgO based sensors. Interestingly, under the exposure of 120 ppm of H2S, [email protected]MgO 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 (Tapplied) up to 200 °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 CDots for high response, low power-consumption, high repeatability and high stability.