A Dynamically Reconfigurable Ambipolar Black Phosphorus Memory Device

Abstract

Nonvolatile charge-trap memory plays an important role in many modern electronics technologies, from portable electronic systems to large-scale data centers. Conventional charge-trap memory devices typically work with fixed channel carrier polarity and device characteristics. However, many emerging applications in reconfigurable electronics and neuromorphic computing require dynamically tunable properties in their electronic device components that can lead to enhanced circuit versatility and system functionalities. Here, we demonstrate an ambipolar black phosphorus (BP) charge-trap memory device with dynamically reconfigurable and polarity-reversible memory behavior. This BP memory device shows versatile memory properties subject to electrostatic bias. Not only the programmed/erased state current ratio can be continuously tuned by the back-gate bias, but also the polarity of the carriers in the BP channel can be reversibly switched between electron- and hole-dominated conductions, resulting in the erased and programmed states exhibiting interchangeable high and low current levels. The BP memory also shows four different memory states and, hence, 2-bit per cell data storage for both n-type and p-type channel conductions, demonstrating the multilevel cell storage capability in a layered material based memory device. The BP memory device with a high mobility and tunable programmed/erased state current ratio and highly reconfigurable device characteristics can offer adaptable memory device properties for many emerging applications in electronics technology, such as neuromorphic computing, data-adaptive energy efficient memory, and dynamically reconfigurable digital circuits.

Stabilizing ultra-thin black phosphorus with in-situ-grown 1 nm-Al2O3 barrier

“…Also, numerous attempts have focused on the passivation via a relatively thick (10 nm or above) Al 2 O 3 layer grown on top of the BP flakes by ALD. 12,[22][23][24][25][26][27][28][29][30][31] Some attempts to reduce the thickness of the capping A 2 O 3 have also been reported. 32 Thin capping may simultaneously passivate and serve as a tunnel barrier (which may even lead to improved electrical contacts 33,34 ) representing a double advantage over thick capping in which electrical contacts must be patterned before passivation (ex-situ).…”

Recent Advances in Black Phosphorus‐Based Electronic Devices

“…[51][52][53][54][55][56][57][58] Nonvolatile charge-trap memory is a popular type of solidstate memory technology that offers its excellent data storage performance and device scalability. In addition to these devices and modules operating with fixed characteristics, BP, being a promising layered semiconductor, has also been exploited for application in nonvolatile memory and circuits, which are regarded as critical components in many emerging electronic applications including neuromorphic computing, efficient data storage, as well as dynamically reconfigurable digital circuits.…”

“…[52,55,59] Compared with other 2D materials, for instance, MoS 2 , BP has the advantage of ambipolar transport characteristics. [52,56] For example, Li et al demonstrated nonvolatile floating-gate memories based on BP/h-BN/MoS 2 stacked heterostructure, with the few-layer BP, h-BN, and MoS 2 acting as the channel layer, tunnelling barrier layer, and charge trapping layer, respectively. [52,56] For example, Li et al demonstrated nonvolatile floating-gate memories based on BP/h-BN/MoS 2 stacked heterostructure, with the few-layer BP, h-BN, and MoS 2 acting as the channel layer, tunnelling barrier layer, and charge trapping layer, respectively.…”

“…[52,56] For example, Li et al demonstrated nonvolatile floating-gate memories based on BP/h-BN/MoS 2 stacked heterostructure, with the few-layer BP, h-BN, and MoS 2 acting as the channel layer, tunnelling barrier layer, and charge trapping layer, respectively. The versatile charge-trap memory properties have also been demonstrated by Tian et al [56] In their work, Al 2 O 3 was used as the charge trapping layer. The versatile charge-trap memory properties have also been demonstrated by Tian et al [56] In their work, Al 2 O 3 was used as the charge trapping layer.…”

An Optoneuronic Device with Realistic Retinal Expressions for Bioinspired Machine Vision

“…Alternatively, the study of memristors as artificial synaptic devices has been gaining momentum since the discovery of the reversible resistive switching effect . Within this realm, recent developments of hybrid electrophotonic responsive devices may prove to be a leading indicator for the evolution of intelligent, artificial neuron‐based VPAs . Such systems were envisioned as being able to mimic the performance of biologic eyes without the need for external cameras or processors .…”