基于p-Se/Al_2O_3/n-ZnO纳米棒阵列异质结的自驱动紫外–可见光探测器（英文）

A Self-powered UV-visible Photodetector Based on p-Se/Al_2O_3/n-ZnO Nanorod Array Heterojunction

自驱动光探测器能够在无外加偏压的情况下将光信号转化为电信号,在工业和军事领域有着广泛的应用。本研究报道了p型Se薄膜和n型ZnO纳米棒阵列异质结的可控合成以及它们作为自驱动紫外-可见光探测器的应用。由于在ZnO和Se的界面处形成的内建电场将光生电子–空穴对分离,促使它们向相反方向传输,最终被电极收集,在0偏压下获得了较高的光电流(435 pA),从而实现无线的自驱动光电探测。并且,在Se和ZnO界面处沉积的Al_2O_3层有效降低了暗电流。最终,此器件在500 nm的单色光下显示了高响应率55μA·W^(–1)和大比探测率5×1010 Jones,并表现出了极快的响应速度(上升时间0.9 ms,衰减时间0.3 ms)。

Self-powered photodetector is capable of transforming radiation signals to electronic signals without assistance of external power supply, which is widely utilized in industry and military. Herein, p-Se/n-ZnO nanorod array heterojunction was successfully synthesized and its application as UV-visible photodetector was explored. Due to the proper built-in electric field at the interface of ZnO and Se, the photogenerated electrons and holes are separated and transported in opposite directions, giving rise to high photocurrent at zero bias. Thus, this heterojunction can work as an independent and wireless self-powered photodetector. Introduction of Al2O3 interlayer between Se and ZnO efficiently reduces the dark current. The resulting device achieves high responsivity of 55 μA.W^–1 and specific detectivity of 5×10^10 Jones at 500 nm, as well as fast response speed (rise time of 0.9 ms and decay time of 0.3 ms).