Attributed to its excellent physicochemical properties, graphene (GR) has very active applications in the fields of catalysis, optoelectronic devices, and battery electrode materials. However, until now, regulating the type and density of carriers in GR is still crucial for its practical applications. Here, reduced graphene oxide (RGO)-Bi₂Te₃ heterojunctions doped with different contents were prepared by a simple one-step method. The Bi₂Te₃ materials containing different RGO were made into broadband (365–850 ​nm) photoelectrochemical-type detectors, and the effects of the doping amount of RGO on the optoelectronic behavior of the devices and the intrinsic operation mechanism of the devices were investigated in detail. The results show that the values of I_ph/I_dark, R_i, and D* of Bi₂Te₃/RGO heterojunction devices obtained with 1 ​mg of RGO doping are 412, 6.072 ​mA/W, and 2.406 ​× ​10¹⁰ Jones, respectively. It is anticipated that this work will provide a research basis for future quantitative tuning of the performance of micro-nano devices by GR.

Self-powered full-spectrum photodetectors (PDs) offer numerous advantages, such as broad application fields, high precision, efficiency, and multi-functionality, which represent a highly promising and potentially valuable class of detectors for future development. However, insensitive response to solar-blind ultraviolet (UV) and complex and expensive preparation processes greatly limit their performance and practical application. In this study, a self-powered full-spectrum Bi₂Se₃/a-Ga₂O₃/p-Si heterojunction PD with high sensitivity for solar-blind UV band prepared by a simple and low-cost two-step synthesis method is presented. Experiments results reveal that the developed PD has an excellent performance, such as high sensitivity from 200 to 850 nm, and a responsivity of 1.38 mA/W as well as a detectivity of 3.22 × 10¹⁰ Jones under 254 nm light at zero bias. Additionally, the unencapsulated device displays exceptional stability and imaging capabilities. It is expected that Bi₂Se₃/a-Ga₂O₃/p-Si heterojunction PD with a simple and low-cost synthesis method has great potential for self-powered full-spectrum photodetectors.

Broadband photodetectors with self-driven functions have attracted intensive scientific interest due to their low energy consumption and high optical gain. However, high-performance broadband self-driven photodetectors are still a significant challenge due to the complex fabrication processes, environmental toxicity, high production costs of traditional 3D semiconductor materials and sharply raised contact resistance, severe interfacial recombination of 2D materials and 2D/3D mixed dimension heterojunction. Here, 1D p-Te/2D n-Bi₂Te₃ heterojunctions are constructed by the simple and low-cost hydrothermal method. 1D p-Te/2D n-Bi₂Te₃ devices are applied in photoelectrochemical (PEC) photodetectors, with their high performance attributed to the good interfacial contacts reducing interface recombination. The device demonstrated a broad wavelength range (365–850 nm) with an I_ph/I_dark as high as 377.45. The R_i, D*, and external quantum efficiency (EQE) values of the device were as high as 12.07 mA/W, 5.87 × 10¹⁰ Jones, and 41.05%, respectively, which were significantly better than the performance of the prepared Bi₂Te₃ and Te devices. A comparison of the freshly fabricated device and the device after 30 days showed that 1D p-Te/2D n-Bi₂Te₃ had excellent stability with only 18.08% decay of photocurrent. It is anticipated that this work will provide new emerging material for future design and preparation of a high-performance self-driven broadband photodetector.