Mixed-dimensional heterostructures opened up a new avenue for fundamental physics studies and applied nanodevice design. Mixed-dimensional heterostructures present considerable freedom in material selection and synergistic advantages of different dimensionalities.
The high optical absorption cross-section and high absorption cross-sections of mixed-dimensional perovskites-ZnO heterostructures ensured the applications in optoelectronics and photon-harvesting technologies. However, due to the challenge in designing and constructing a proper 1D-3D p-n junction, their electronic properties and potential application are still unclear.
Recently, a research team led by Profs. SUN Lianfeng and XIE Liming from the National Center for Nanoscience and Technology (NCNST) of the Chinese Academy of Sciences (CAS) demonstrated the liquid-phase preparation of 3D CsPbBr3-1D ZnO p-n heterojunctions. This work was published on Nano Today.
Herein, the researchers constructed a type of CsPbBr3 – ZnO p-n junction by liquid-phase growth of crystalline CsPbBr3 microplates on ZnO nanowires. This p-n junction exhibits excellent properties of p-n diode and serves as high-performance rectifier and photodetector.
When the CsPbBr3 – ZnO p-n junction is employed as a rectifier, it shows characteristics of ambipolar transfer and the rectification ratio reaches up to 106.
In addition, if the CsPbBr3 – ZnO p-n junction is used as a photodetector, it covers light from ultraviolet to visible light. High photoelectric switching ratio (107), responsivity (3.5×103A/W), detectivity (6.6×1013 Jones) and external quantum efficiency (1.7 ×106 %) are obtained under 254 nm light illumination. Meanwhile, the switching ratio, detectivity and external quantum efficiency are 103, 41.5 A/W, 4.96×1012 Jones and 1.086×103 %, respectively, under 473 nm laser illumination.
Furthermore, the decay length of photo-generated carriers in CsPbBr3 -ZnO heterojunction is demonstrated longer than that in original CsPbBr3 crystal, which is further controlled by adjusting the potential barriers between the CsPbBr3 and ZnO with a tunable external electric field.
This material system would offer a new platform for the fundamental investigation of electronic and photoelectronic properties of mixed-dimensional heterostructures.
This work was supported by Major Nano-projects of Ministry of Science and Technology of China, the National Natural Science Foundation of China, GBA Research Innovation Institute for Nanotechnology, Baotou Rare Earth Research and Development Centre, Chinese Academy of Sciences, Key Research Program of Frontier Sciences of CAS and Strategic Priority Research Program of CAS.
Figure: perovskites-ZnO heterostructures
National Center for Nanoscience and Technology