Gate‐Dependent Tunnelling Current Modulation of Graphene/hBN Vertical Heterostructures. Issue 7 (16th April 2018)

• Record Type: Journal Article
• Authors: Iqbal, Muhammad Zahir; Siddique, Salma; Khan, Muhammad Farooq; Rehman, Atteq ur; Rehman, Adil; Eom, Jonghwa
• Is Part Of: Advanced engineering materials. Volume 20:Issue 7(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-04-16
• Subjects: graphene -- threshold voltages -- tunneling current -- vertical heterostructures; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201800159
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : Combining with layered thin crystalline films, graphene has expanded its application scope beyond the regime where a gapless semimetal cannot serve. Here, we report the modulation of tunneling characteristics in graphene/hexagonal boron nitride (hBN) vertical heterostructure at different interlayer hBN thickness. These results signify an upshift in threshold voltages with hBN layer thickness. Furthermore, the gate‐dependent tunneling characteristics of the device has been demonstrated. The back‐gate voltages are used to adjust the fermi level of bottom graphene layer, which in turns tune the threshold voltages and tunneling current through ultrathin hBN layer. Our findings offer an effective tool to modulate the tunneling characteristics of vertical transistors for their potential applications in high frequency logic and tunnel devices. Abstract : The two‐dimensional materials receives a remarkable cornucopia of new physics, particularly to their unusual electronic properties. Here, we report the modulation of tunneling characteristics in atomically thin graphene/hBN vertical heterostructures. The application of Vg through back‐gate provide an additional control of graphene charge carrier density. The Vth of GBN‐3 device is larger compared to GBN‐1 and GBN‐2 device, due to the thicker interlayer hBN film. Moreover, the on–off ratio of the device is also improved by increasing the interlayer thickness. Such stacking of layered materials produce an innovative class of composite structures, which may found great potential in future high frequency logic and tunnel devices.