Gallium phosphide nanoribbon-based carbon monoxide sensors: insights from first principles study

Abstract

The priority of research efforts over the past two decades has been focused on the effective detection of harmful gases and the development of small, efficient, and reliable nanodimensional sensors. The adsorption of carbon monoxide (CO) gas molecules on zigzag gallium phosphide nanoribbons (zGaPNRs) has been studied using first-principle calculations within the context of Density Functional Theory (DFT). Here, we have evaluated the potential of single-atom thick zGaPNRs in different configurations of nanoribbons for the detection of CO. Many possible configurations of studying the CO molecule adsorption on zGaPNRs have been explored. It is established that the interaction of CO molecules has an impact on the electrical and transport properties of zGaPNRs. The H-GaP-H is the most stable structure with the binding energy ([Formula: see text]) of −5.70[Formula: see text]eV. The stability is compromised with CO adsorption with CO-GaP-CO being the least stable structure. Pristine structure is semiconducting with the energy band gap ([Formula: see text]) of −3.95[Formula: see text]eV. The computed sensitivity (S) values are found to be highest for Co-GaPNRs with the S value of [Formula: see text] and the least sensitive structure is H-GaP-CO with the computed S as [Formula: see text]. Additionally, it is noted that CO molecules always establish a stable chemical bond with the nanoribbon edges through the C-side. The unique behavior is revealed by the transport characteristics, which demonstrates that when CO adsorption occurs near the Ga edge, the current magnitude is noticeably greater. Our research demonstrates the potential of specific CO adsorption and detection for the development of nanosensors.