Astability versus Bistability in van der Waals Tunnel Diode for Voltage Controlled Oscillator and Memory Applications

Abstract

Van der Waals (vdW) tunnel junctions are attractive due to their atomically sharp interface, gate tunablity, and robustness against lattice mismatch between the successive layers. However, the negative differential resistance (NDR) demonstrated in this class of tunnel diodes often exhibits noisy behaviour with low peak current density, and lacks robustness and repeatability, limiting their practical circuit applications. Here we propose a strategy of using a 1L-WS${}_2$ as an optimum tunnel barrier sandwiched in a broken gap tunnel junction of highly doped black phosphorus (BP) and SnSe${}_2$. We achieve high yield tunnel diodes exhibiting highly repeatable, ultra-clean, and gate tunable NDR characteristics with a signature of intrinsic oscillation, and a large peak-to-valley current ratio (PVCR) of 3.6 at 300 K (4.6 at 7 K), making them suitable for practical applications. We show that the thermodynamic stability of the vdW tunnel diode circuit can be tuned from astability to bistability by altering the constraint through choosing a voltage or a current bias, respectively. In the astable mode under voltage bias, we demonstrate a compact, voltage controlled oscillator without the need for an external tank circuit. In the bistable mode under current bias, we demonstrate a highly scalable, single element one-bit memory cell that is promising for dense random access memory applications in memory intensive computation architectures.

References in corpus (6)

• Accessing the transport properties of pristine few-layer black phosphorus by van der Waals passivation in inert atmosphere
• Twist-controlled resonant tunnelling in graphene-boron nitride-graphene heterostructures
• Electrical characterization of fully encapsulated ultra thin black phosphorus-based heterostructures with graphene contacts
• Layer-dependent properties of SnS2 and SnSe2 novel two-dimensional materials
• Gate- and Light-Tunable Negative Differential Resistance with High Peak Current Density in 1T-TaS${}_2$/2H-MoS${}_2$ T-Junction
• S-type Negative Differential Resistance in Semiconducting Transition-Metal Dichalcogenides

Cited by in corpus (1)

• A High-Quality Entropy Source Using van der Waals Heterojunction for True Random Number Generation