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论文类型：期刊论文

发表时间：2019-09-01

发表刊物：SMALL

收录刊物：SCIE

卷号：15

期号：38

ISSN号：1613-6810

关键字：Au nanoparticles; avalanche photodetectors; black phosphorus; plasmonic effects

摘要：A highly sensitive avalanche photodetector (APD) is fabricated by utilizing the avalanche multiplication mechanism in black phosphorus (BP), where a strong avalanche multiplication of electron-hole pairs is observed. Owing to the small bandgap (0.33 eV) of the multilayer BP, the carrier multiplication occurs at a significantly lower electric field than those of other 2D semiconductor materials. In order to further enhance the quantum efficiency and increase the signal-to-noise (S/N) ratio, Au nanoparticles (NPs) are integrated on the BP surface, which improves the light absorption by plasmonic effects. The BP-Au-NPs structure effectively reduces both dark current (approximate to 10 times lower) and onset of avalanche electric field, leading to higher carrier multiplication, photogain, quantum efficiency, and S/N ratio. For the BP-Au-NPs APD, it is obtained that the external quantum efficiency (EQE) is 382 and the responsivity is 160 A W-1 at an electric field of 5 kV cm(-1) (V-d approximate to 3.5 V, note that for the BP APD, EQE = 4.77 and responsivity = 2 A W-1 obtained at the same electric field). The significantly increased performance of the BP APD is promising for low-power-consumption, high-sensitivity, and low-noise photodevice applications, which can enable high-performance optical communication and imaging systems.