Broadband photodetector has wide applications in the field of remote sensing, health monitoring and medical imaging. Two-dimensional (2D) materials with narrow bandgaps have shown enormous potential in broadband photodetection. However, the device performance is often restricted by the high dark currents. Herein, we demonstrate a high performance broadband photodetector by constructing Bi₂O₂Se/BP van der Waals heterojunction. The device exhibits a p-n diode behavior with a current rectification ratio of ∼20. Benifited from the low dark current of the heterojunction and the effective carrier separation, the device achieves the responsivity (R) of ∼ 500 A/W, ∼ 4.3 A/W and ∼ 2.3 A/W at 700 nm, 1310 nm and 1550 nm, respectively. The specific detectivity (D*) is up to ∼ 2.8 × 10¹¹ Jones (700 nm), ∼ 2.4 × 10⁹ Jones (1310 nm) and ∼ 1.3 × 10⁹ Jones (1550 nm). Moreover, the response time is ∼ 9 ms, which is more than 20 times faster than that of individual BP (∼ 190 ms) and Bi₂O₂Se (∼ 180 ms) devices.

宽带光电探测器在遥感，健康监测和医学成像领域具有广泛的应用。具有窄带隙的二维（2D）材料在宽带光电检测中显示了巨大的潜力。但是，器件性能通常受到高暗电流的限制。本文中，我们通过构建Bi ₂ O ₂ Se / BP van der Waals异质结展示了一种高性能的宽带光电探测器。该器件在电流整流比约为20的情况下具有pn二极管特性。得益于异质结的低暗电流和有效的载流子分离，该器件在700 nm，1310 nm和1550 nm处的响应度（R）为〜500 A / W，〜4.3 A / W和〜2.3 A / W。 ， 分别。特定的侦探性（D *）高达2.8×10 ¹¹ Jones（700 nm），2.4×10 ⁹ Jones（1310 nm）和1.3×10 ⁹ Jones（1550 nm）。此外，响应时间约为9毫秒，比单个BP（约为190毫秒）和Bi ₂ O ₂ Se（约为180毫秒）设备的响应时间快20倍以上。