Influence of the substitution of different functional groups on the gas sensing and light harvesting efficiency of zero-dimensional coronene quantum dot: A first principle DFT study

Abstract

The present study accounts for the structural and electronic properties of a zero-dimensional coronene quantum dot (QD) and its substituted structures with seven different functional groups. The substitution of functional groups lead to the alteration of the centrosymmetric geometry of the coronene flake and thus, incredible properties were observed for the functionalized QDs. The increment in the band gap after the substitution of the functional groups was responsible for the increase in the chemical stability. The cohesive energy however decreased for the functional QDs. Fourier transform Infrared spectra were traced for all the QDs to confirm the availability of the functional groups and their participation in the chemical reactivity. After the substitution of functional groups, the extremely enhanced light harvesting efficiency of functionalized QDs was obtained. Furthermore, the sensing capability of the functionalized QDs for CO, CO2, and NH3 was also calculated and it was found that C-cyano, C-nitro, C-nitroso, C-pyrrolidine, and C-thionyl QDs have better sensing capabilities for CO2 molecules. C-pyrrolidine had the highest value of light harvesting efficiency of about 96%. This reflects the potential photosensitive candidature of C-pyrrolidine. Therefore, the present study sets a perfect benchmark for designing and fabricating efficient photosensitive materials and gas-sensing devices using the introduced QDs in the near future.