Broadband photodetection of 2D Bi2O2Se–MoSe2 heterostructure
2019
Yang, Tao | Li, Xing | Wang, Liming | Liu, Yiming | Chen, Kaijian | Yang, Xun | Liao, Lei | Dong, Lin | Shan, Chong-Xin
Due to their unique structure and photoelectrical properties, two-dimensional (2D) materials have attracted enormous attention on next-generation optoelectronic devices. Recently, the newly discovered 2D layered Bi₂O₂Se has exhibited outstanding sensitivity and optoelectronic properties. However, the performance of these 2D layered Bi₂O₂Se photodetectors can be limited by the high dark currents. The suitable band structure of 2D MoSe₂ can form a type-II heterojunction with Bi₂O₂Se, which can reduce the dark current, modulate the interlayer transition energy and induce the charge spatial separation. Herein, we demonstrated a photodetector based on the heterojunction fabricated by van der Waals assembly between Bi₂O₂Se and few-layer MoSe₂, showing visible to near-infrared detection range. Moreover, our results showed that the dark current of this photodetector was significantly reduced and the Iₒₙ/Iₒff ratio was greatly improved. Importantly, it exhibited a broad detection range from 405 to 808 nm with a responsivity of 413.1 mA W⁻¹, a high detectivity of 3.7 × 10¹¹ Jones (at 780 nm) at room temperature. Compared with the 2D Bi₂O₂Se photodetector, the photocurrent response and recovery time in the heterojunction photodetector was greatly reduced from 1.92/1.31 to 0.79/0.49 s at room temperature. Our results showed that 2D Bi₂O₂Se/MoSe₂ heterojunction has a great potential for broadband and fast photodetection.
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