Preparation of Nanostructured HgI2 Nanotubes/Si Photodetector by Laser Ablation in Liquid

Abstract

In this work, HgI 2 nanotubes/Si heterojunction has been prepared by pulsed laser ablation in ethanol at laser uence of 12.7 J/cm 2 . The structural and optical properties of HgI 2 nanotubes (NTs) are studied.The X-ray diffraction (XRD) result shows the presence of the mixture of tetragonal and orthorhombic phases of HgI 2 . The optical properties results show that the optical energy gap of HgI 2 NTs was 2.98 eV measured at room temperature. The photoluminescence (PL) spectra of HgI 2 display a single emission centered at 535nm. Fourier transformed infrared (FT-IR) results reveal the existence of small bonds at 612 and 1102 cm − 1 . Scanning electron microscope (SEM) image show formation of nanotubes and spherical nanoparticles with average particle size of 23nm. Transmission electron microscope (TEM) image of HgI 2 con rms the formation of nanotubes morphology with an average diameter of 80nm and an average length of 1.6µm. The I-V curve of HgI 2 NTs/p-Si heterojunction were measured at dark and illumination.The responsivity of HgI 2 NTs/p-Si heterojunction photodetector is 1.09A/W at 450 and the detectivity and external quantum e ciency are 3.6 ×10 12 Jones at 450 and 3×10 2 % at 400nm, respectively, without using post annealing.