Ultrasensitive 2D Bi₂O₂Se Phototransistors on Silicon Substrates

Abstract

2D materials have shown great potential for high-performance electronic devices, thanks to their dangling-bond-free surface and atomic thickness which bring merits of high carrier mobility, efficient channel current regulation, and higher degree of vertical integration. [1][2][3][4][5] Many 2D semiconducting materials have shown outstanding phototransistor performance, such as MoS 2 , [6][7][8] WSe 2 , [9,10] GaTe, [11,12] and SnSe 2 , [13][14][15] because of their suitable energy bandgap and high mobility.

Insights into the Control of Optoelectronic Properties in Mixed‐Stacking Charge‐Transfer Complexes

“…Under UV illumination (405 nm) with increasing power density from 6.7 to 866.8 μW cm −2 , I light is markedly enhanced and the corresponding photocurrent ( I ph = I light − I dark ) was instantly generated and gradually increased from 5.2 to 111 nA ( V G =10 V, Figure b), and the maximum P value (photocurrent on/off ratio) was estimated to be 353 (light intensity: 866.8 μW cm −2 , V G =20 V). The I ph value can be expressed by a simple law ( I ph ∝ P 0.61 ) from the log–log plot of I ph dependence on the light intensity and exhibits a sublinear response, which can be ascribed to the process involved in the trap states induced by the defects or charge impurities present in the TMCA microrod and the semiconductor/dielectric interface (Figure d) . In addition, the threshold voltage shift (Δ V th , towards more positive values) also exhibits an approximately linear relationship as a function of the power density, and the maximum Δ V th is up to 73 V (Figure e), which is derived from filling of the trap sites by the photogenerated carriers, which causes injection and accumulation of additional holes in the active layer .…”

2D In2S3 Nanoflake Coupled with Graphene toward High‐Sensitivity and Fast‐Response Bulk‐Silicon Schottky Photodetector

“…Figure c depicts the measured photocurrent of the In 2 S 3 /graphene/Si PD as a function of 405 nm light intensity at a fixed V ds = −2 V. The photocurrent can be expressed by a simple power law I ph ∝ P 0.18 for weak light and I ph ∝ P 0.02 for strong light. Here, the nonunity of exponent can be associated with the complex process of electron–hole excitation, trapping, and recombination within the In 2 S 3 /graphene/Si heterojunction …”

2D Metal Chalcogenides for IR Photodetection

“…Very lately, a new star ternary material Bi 2 O 2 Se joins into the 2D family . Bi 2 O 2 Se possesses high Hall mobility (29 000 cm 2 V −1 s −1 at 1.9 K and 450 cm 2 V −1 s −1 at room temperature) and appropriate bandgap of 0.8 eV, which pave the way for high sensitivity and fast response IR photodetection.…”