Atomically Thin 2D Crystals for Nanoelectronics devices

<strong>Special Centre for Nano Sciences Jawaharlal Nehru University</strong> a Seminar on <strong>Atomically Thin 2D Crystals for Nanoelectronics devices</strong> by <strong>Dr. Dattatray Late </strong> CSIR-National Chemical Laboratory, Pune Date: <strong>14th march 2015</strong> <strong>Abstract:</strong> Atomically thin 2D-dimensional materials have attracted significant attention from the scientific community in the last few years due to their potential exotic transport physics and prospects for technological applications in various fields. As the first prototype of layered structures, graphene and graphene like inorganic layered materials has been ynthesized and widely studied for its unusual electrical, optical, mechanical properties. The main advantage of graphene-based transistors is the associated carrier high mobilities. However, several problems remain with graphene due to absence of a band gap which is essential for transistor applications. The discovery of graphene opened the door to 2D crystal materials. Following graphene, there has been emerging interest in exploring other single-sheet 2-D layered structures such as MoS2, WS2, MoSe2, WSe2 etc. semiconductor with a finite and direct band gap in contrast to graphene which is gapless and thus can potentially find widespread applications in next generation electronics and energy technology [1-5]. Being monolayer in thickness, their performances in transistor devices are highly dependent on their interface with the substrate and atmospheric adsorbates. We attempt to address few issues by fabricating single layer MoS2 transistors on self assembled, ultrathin, hybrid organic-inorganic, and high-k nanodielectrics. We observe low operating voltages and improved performance. Also, uniform coverage of MoS2 transistors with silicon nitride grown by plasma-enhanced chemical vapor deposition completely removes the hysteresis while the device mobility can be improved dramatically [3-4]. Atomically thin MoS2, WS2, MoSe2 shows sensitive detection of gases such as NH3 and NO2 at room temperature and atmospheric pressure [5]. Also, the few layers of MoS2, WS2, SnS2, VS2 and its composite with graphene were suitable for use in next generation field emitter devices due enhanced electron emission performance [6-8]. KEYWORDS: Layered Materials, Nanodielectrics, Transistor, Sensors, Field Emission. *E-mail: dj.late[at]ncl[dot]res[dot]in, datta099[at]gamil[dot]com References: [1] D. J. Late, B. Liu, H. Matte, C. N. R. Rao, V. P. Dravid, Adv. Fun. Mat., 22 (2012) 1894. [2] D. J. Late, B. Liu, J. Liu, A. Yan, H. Matte, M. Grayson, C. N. R. Rao, V. P. Dravid, Adv. Mat., 24 (2012) 3549. [3] D. J. Late, B. Liu, H. Matte, V. P. Dravid, C. N. R. Rao, ACS Nano, 6 (2012) 5635. [4] D. Jariwala, V. K. Sangwan, D. J. Late, et. al. Appl. Phys. Lett. 102 (2013)173107. [5] D. J. Late, Y. Huang, et. al. ACS Nano 7 (2013) 4879–4891. [6] C. Rout, P. Joshi, R. Kashid, D. Joag, M. More, A. Simbeck, M. Washington, S. K. Nayak, D. J. Late, Sci. Rep. (Nature) 3, (2013) 3282. [7] R.V. Kashid, D. J. Late, M. A. More, D. S. Joag, V. P. Dravid, Small, 9 (2013), 2730. [8] D. J. Late, P. A. Shaikh, R. Khare, R. V. Kashid, M. Chaudhary, M. A. More, S. B. Ogale, ACS Appl. Mater. Interfaces 2014. DOI: 10.1021/am503464h. [9] C. S. Rout, R. Tiwari, R. V. Kashid, D. S. Joag, M. A. More, A. J. Simbeck, M. Washington, S. K. Nayak, D. J. Late, Europ J. Inorganic Chem. 2014. DOI: 10.1002/ejic.201402448. [10] C. S. Rout, P. D. Joshi, R. V. Kashid, D. S. Joag, M. A. More, A. Simbeck, M. Washington, S. K. Nayak, D. J. Late, Appl. Phy Lett. 105 (2014) 043109.