摘要： Semiconducting p-n heterojunctions, serving as the basic unit of modern electronic devices, such as photodetectors, solar-energy conversion devices, and light-emitting diodes (LEDs), have been extensively investigated in recent years. In this work, high performance self-powered broadband photodetectors were fabricated based on vertically stacked p-n heterojunctions though combining p-type WSe2 with n-type Bi2Te3 via van der Waals (vdW) epitaxial growth. Devices based on the p-n heterojunction show obvious current rectification behaviors in the dark and superior photovoltaic characteristics under light irradiation. Maximum short circuit current of 18 nA and open circuit voltage of 0.25 V can be achieved with the illumination light of 633 nm (power density: 26.4 mW/cm2), which are among the highest values compared with the ever reported 2D vdW heterojunctions synthesized by CVD method. Benefiting from the broadband absorption of the heterostructures, the detection range can be expanded from visible to near-infrared (375-1550 nm). Moreover, ascribing to the efficient carriers separation process at the junction interfaces, the devices can be further employed as self-powered photodetectors, where fast response time (≈210 μs) and high responsivity (20.5 A/W at 633 nm and 27 mA/W at 1550 nm) are obtained under zero bias voltage. The WSe2/Bi2Te3 p-n heterojunction-based self-powered photodetectors with high photoresponsivity, fast photoresponse time and broad spectral response will find potential applications in high speed and self-sufficient broadband devices.