Atomic layer deposition – state-of-the-art approach to nanoscale hetero-interfacial engineering of chemical sensors electrodes: A review

Chemical sensors based on atomically-thin two-dimensional (2D) semiconductors and their hetero-structures are promising candidates for sensing various agents with unipolar sensitivity, excellent selectivity, high responsivity and great long-term stability for versatile applications at the wide working temperature range. Further improvement of sensors’ main characteristics is inseparably connected to the hetero-interfacial engineering of few-nm thick sensing electrodes (SE) at nanoscale. Review focuses on advantages and advances of the atomic layer deposition (ALD) enabling technology among others different SE preparation methods and elaborates the devised strategies towards SE fabrication process, their phase compositions and nano-architectures as well as catalytic effects of 2D nanomaterials forming hetero-structured SE. The discussed ALD advantages ensure the employment of this technique for further development of hetero-structured 2D semiconductors with unique properties. Results, mainly obtained during last few years for ALD-enabled gaseous, aqueous and bio-sensors have been used for showing an opportunity of nano-structural engineering of 2D hetero-structures for optimization of sensing characteristics. Critical thinking and established ideas regarding the future development of hetero-structured 2D hybrid materials-based chemical sensors are discussed.