Exploitation of Bi₂O₂Se/graphene van der Waals heterojunction for creating efficient photodetectors and short‐channel field‐effect transistors

Abstract

The formation of heterojunction within solid‐state devices enables them with eventually high performances, but provides a challenge for material synthesis and device fabrication because strict conditions such as lattice match are needed. Herein, we show a facile method to fabricate a van der Waals (vdW) heterojunction between two‐dimensional (2D) bismuth oxyselenide (Bi2O2Se) and graphene, during which the graphene is directly transferred to the Bi2O2Se and served as a low‐contract‐resistant electrode with small work function mismatch (~50 meV). As an optoelectronic device, the Bi2O2Se/graphene vdW heterojunction allows for the efficient sensing toward 1200‐nm incident laser. Regarding the application of field‐effect transistors (FETs), the short‐channel (50 nm) sample can be synthesized by utilizing these two 2D materials (ie, channel: Bi2O2Se; drain/source terminal: graphene) and the n‐type characteristic can be observed with the accordant field modulation. It is confirmed that we show a simple way to prepare the vdW heterojunction which is aiming to the high‐performance applications among optoelectronics and FETs.

Record‐Low Subthreshold‐Swing Negative‐Capacitance 2D Field‐Effect Transistors

“…Hence, it is urgent to develop novel prototype devices that can break the thermionic limit of SS to achieve sub-60 mV dec −1 . [3,4] To this end, several steep-slope device systems such as nanoelectromechanical FETs (NEMFETs), [5,6] tunnel FETs (T-FETs), [7,8] Dirac-source FETs (DS-FETs), [9] impact ionization FETs (II-FETs), [10] and negativecapacitance FETs (NC-FETs) [11][12][13][14][15][16][17][18] have been proposed and developed to realize sub-60 mV dec −1 SS potentially. For instance, compared with MOSFET, normal dielectric materials are replaced by ferroelectric/dielectric systems in NC-FETs to achieve low SS below 60 mV dec −1 under the condition of capacitance matching.…”

Bi2O2Se/BP van der Waals heterojunction for high performance broadband photodetector

“…Because of the absorption of both BP and Bi 2 O 2 Se to infrared light, R reaches ∼ 9.5 A/W, ∼ 4.3 A/W and ∼ 2.3 A/W at 850 nm, 1330 nm and 1550 nm, respectively. This is at a superior level among the BP or Bi 2 O 2 Se based photovoltaic photodetectors, as summarized in Figure4(f)[27][28][29][30][31][32][33][34][35][36][37][38]. Whilst D* is calculated to be ∼ 5.3 × 10 9 Jones, ∼ 2.4 × 10 9 Jones and ∼ 1.…”

Cross‐Substitution Promoted Ultrawide Bandgap up to 4.5 eV in a 2D Semiconductor: Gallium Thiophosphate

“…[5,12] Recently, the emergence of photodetectors based on 2D materials has opened up an avenue to circumvent the abovementioned dilemma owing to their free surface dangling bonds. [13,14] In addition, 2D materials usually have atomic thickness, [15] high specific surface area, [16] and strong light-matter interaction, [17] which can provide high responsivity and photoconductive gain in nanoscale photodetectors. [18][19][20][21][22] Such 2D materials Exploring 2D ultrawide bandgap semiconductors (UWBSs) will be conductive to the development of next-generation nanodevices, such as deep-ultraviolet photodetectors, single-photon emitters, and high-power flexible electronic devices.…”