Promising Rare-Earth-Doped, Electrospun, ZnO Nanofiber N-type Semiconductor for Betavoltaic Batteries.

Betavoltaic batteries, as a kind of ultimate battery, have attracted much attention. ZnO is a promising wide-bandgap semiconductor material that has great potential in solar cells, photodetectors, and photocatalysis. In this study, rare-earth (Ce, Sm, and Y)-doped ZnO nanofibers were synthesized using advanced electrospinning technology. The structure and properties of the synthesized materials were tested and analyzed. As betavoltaic battery energy conversion materials, the results show that rare-earth doping increases the UV absorbance and the specific surface area and slightly reduces the band gap. In terms of electrical performance, a deep UV (254 nm) and X-ray source (10 keV) were used to simulate a radioisotope β-source to evaluate the basic electrical properties. Among them, the output current density of Y-doped ZnO nanofibers can reach 87 nA·cm, which is 78% higher than that of traditional ZnO nanofibers, by deep UV. Besides, the photocurrent response of Y-doped ZnO nanofibers is superior to that of Ce-doped and Sm-doped ZnO nanofibers by soft X-ray. This study provides a basis for rare-earth-doped ZnO nanofibers as energy conversion devices used in betavoltaic isotope batteries.