Complementary Trilayer–Bulk Black Phosphorus Heterojunction Tunnel Field-Effect Transistor with Subthermionic Subthreshold Swing

Abstract

Reductions in transistor size have improved functionality of transistors and lowered costs of electronic processors. However, as transistors decrease in size, quantum tunneling causes increased leakage currents and power consumption. To resolve power consumption issues, tunnel field-effect transistors (TFETs) utilizing band-to-band tunneling (BTBT) have been suggested. Such devices can overcome the 60 mV/dec subthreshold swing (SS) limit that is a disadvantage of conventional metal-oxide-semiconductor field-effect transistors (MOS-FETs), but only a limited number of TFETs have achieved this at 300 K. Here, we report complementary trilayer−bulk black phosphorus (BP) heterojunction TFETs with an SS min of 17.7 mV/dec (21.3 mV/dec) for p-type (n-type) operation. In the same devices, SS ≫ 60 mV/dec is exhibited when BTBT occurs within the trilayer BP, indicating that BTBT between the heterojunction of a trilayer−bulk BP is the key to achieving a subthermionic SS. Our work demonstrates the utility of BP heterojunctions in developing energy-efficient switches.

Device simulation of GeSe homojunction and vdW GeSe/GeTe heterojunction TFETs for high-performance application

“…To further introduce a homojunction or heterojunction architecture [15][16][17][18][19][20][21] in a TFET is a convincing scheme to continuously promote the Ion compared to a homogenous 2D channel. Experientially, 2D TFETs have been fabricated based on transition metal chalcogenides (TMD) and black phosphorene (BP) with good Ion and SS [24][25][26][27][28][29][30][31]. Inspiringly, a much higher Ion is observed on BP homojunction TFETs than their homogenous counterparts from experiment [29][30][31] and theory [18][19][20].…”

“…Experientially, 2D TFETs have been fabricated based on transition metal chalcogenides (TMD) and black phosphorene (BP) with good Ion and SS [24][25][26][27][28][29][30][31]. Inspiringly, a much higher Ion is observed on BP homojunction TFETs than their homogenous counterparts from experiment [29][30][31] and theory [18][19][20]. The improved Ion by the homojunction arises from the narrower bandgap of a thicker-layer/bulk BP so that the tunneling barrier is narrowed.…”

Defect-Induced Different Band Alignment and Transport of All-Phosphorene Devices from First Principles

“…At the same time, it contains various anisotropic properties which originate from its orthorhombic crystal structure . It consequently demonstrates promising advantages in numerous fields, such as spintronics, − field-effect transistors, , and photodetectors, − which are beneficial for device applications.…”

Promises of Main-Group Metal Chalcogenide-Based Broken-Gap van der Waals Heterojunctions for Tunneling Field Effect Transistors

“…To overcome this thermal subthreshold limit, a band-to-band tunneling field effect transistor (TFET) is developed in recent years. − In contrast to conventional FETs, the primary mechanism in TFETs , is interband tunneling rather than thermal injection. Consequently, TFETs can achieve a steeper-subthreshold slope with SS < 60 mV/dev. − Accordingly, the power consumption in TFETs can be effectively decreased. However, one challenge of TEFTs is that all fabricated TEFTs have severely limited ON-current.…”