Planar Quasi-1-D Toxic Heavy Metal Nanosensor Based on Zigzag Gallium Nitride Nanoribbon

The potential of gallium nitride nanoribbon (GaNNR) as next-generation sensors for real-time detection of toxic heavy metals (HMs) necessitates a deep understanding of their interaction. The density functional theory (DFT) approach is used for the study of quantum properties of toxic HMs-interacted zigzag GaNNRs (ZGaNNRs). The significant changes in structural and electronic behavior of HM-interacted ZGaNNRs are found when compared to bare ZGaNNR irrespective of their widths. The study of binding energy (Eb) reveals that the lead (Pb)-ZGaNNR-Pb is the most stable structure followed by zinc (Zn)-ZGaNNR-Zn and mercury (Hg)-ZGaNNR-Hg. The Fermi level of HM-interacted ZGaNNRs is observed to be shifted toward the conduction band which predicts the n-type nature of HM-interacted ZGaNNRs. Interestingly, additional electronic states are found in the band structure due to HMs, which exhibit different energy levels with respect to Zn, Hg, and Pb interaction. The calculated density-of-state (DOS) sensitivity is observed to be higher for Zn-ZGaNNR-Zn followed by Pb-ZGaNNR-Pb and Hg-ZGaNNR-Hg. The calculated transport properties of HM-interacted ZGaNNR exhibit higher current values when compared to bare-ZGaNNR devices. Interestingly, the current sensitivity is observed to be maximum for Pb having value 3.3 × 104 at 1 V. As per our findings, it can be observed that the sensitivity of our ZGaNNRs for Pb is the highest. Thus, it can be deployed as a Pb detector. The structural, electronic, and quantum transport properties of HM-interacted ZGaNNRs advocate their potential applications in nanoscaled sensor devices for the toxic HM detector.