High-Responsivity Heterojunction Photodetector Based on Bi2O3-Decorated MWCNTs Nanostructure Grown on Silicon via Laser Ablation in Liquid

We prepared a high-responsivity bismuth oxide Bi2O3 nanoparticles-decorated multiwalled carbon nanotubes MWCNTs/Si heterojunction photodetector by two-step laser ablation in liquid. The structural properties of the hybrid Bi(2)O(3)NPs-decorated MWCNTs were investigated by X-ray diffraction, which revealed the formation of alpha-Bi2O3 NPs with a monoclinic phase and graphite at the C(002) plane. Scanning electron microscopy results show the formation of spherical Bi(2)O(3)NPs attached to well-dispersed MWCNTs. The nanotubes' diameters ranged from 30 to 50 nm, their lengths from 1 to 3 m, and the average particle size of Bi2O3 NPs is 25 nm. The I-V characteristics for the Bi(2)O(3)NPs-decorated MWCNTs/Si photodetector were investigated in the dark and under illumination. The Bi(2)O(3)NPs-decorated MWCNTs/n-Si photodetectors show a responsivity of 1.37 A/W at a wavelength of 560 nm, with a corresponding external quantum efficiency of 3 x 10(2)%. At equilibrium, band alignment for Bi2O3-MWCNTs /Si heterojunction was realized.

Automated summary

A high-responsivity bismuth oxide nanoparticles-decorated multiwalled carbon nanotubes/silicon heterojunction photodetector was prepared using two-step laser ablation in liquid. The structural properties of the hybrid nanoparticles were analyzed, and the presence of alpha-Bi2O3 nanoparticles and graphite at the C(002) plane was confirmed. Scanning electron microscopy revealed the formation of spherical Bi2O3 nanoparticles attached to well-dispersed multiwalled carbon nanotubes. The photodetector showed good responsivity and external quantum efficiency at a wavelength of 560 nm.