In this study, mercury iodide (HgI₂) nanoparticles (NPs) were synthesized by pulsed laser ablation in ethanol at laser fluences of 22.9, 33.1, and 43.3 J/cm². The effect of laser fluence on the structural and optical properties of HgI₂ NPs was studied. X-ray diffraction findings reveal that all synthesized HgI₂ samples were polycrystalline in nature with orthorhombic structure. Absorption peak was appeared at 474 nm and the optical energy gap of HgI₂ NPs decreases from 2.13 to 2.05 eV as laser fluence increased from 22.9 to 43.3 J/cm². Zeta potential (ZP) results confirm that the nanoparticles synthesized at 22.9 and 33.1 J/cm² have high degree of stability. Fluorescence measurements show the presence of several emission bands. Raman spectra of HgI₂ NPs show the presence of six vibration modes centered at 15, 29, 37, 44, 51, and 70 cm⁻¹. Fourier transform infrared (FT-IR) results show the presence of two bonds, namely, C–O and Hg-I. Transmission Electron Microscope (TEM) results showed that the formation of spherical nanoparticles for sample prepared at 22.9 J/cm², 25–75 nm in size. While the nanoparticles synthesized with 33.1 and 43.3 J/cm² exhibit nanorods and nanotubes morphologies, respectively. The dark I–V characteristics of β-HgI₂ NPs/Si heterojunction photodetectors show rectification properties and the junction quality depends on the laser fluence and the best junction characteristics was obtained for heterojunction prepared at 33.1 J/cm². The white light photosensitivity of the HgI₂/p-Si photodetectors was measured at reverse bias under different intensities. The maximum responsivity reached was 3.39A/W at 450 nm for photodetector prepared at 33.1 J/cm².

在这项研究中，碘化汞 (HgI ₂ ) 纳米粒子 (NPs) 是通过在乙醇中以22.9、33.1和 43.3 J/cm ^{2 的}激光能量密度脉冲激光烧蚀合成的。研究了激光能量密度对 HgI ₂ NPs结构和光学特性的影响。X 射线衍射结果表明，所有合成的 HgI ₂样品本质上都是具有正交结构的多晶。吸收峰出现在 474 nm 处，随着激光能量密度从 22.9 增加到 43.3 J/cm ²，HgI ₂ NPs 的光能隙从 2.13 eV 减少到 2.05 eV 。Zeta 电位 (ZP) 结果证实纳米粒子在 22.9 和 33.1 J/cm ^{2 下}合成具有高度的稳定性。荧光测量显示存在几个发射带。HgI ₂ NP 的拉曼光谱显示存在以 15、29、37、44、51和 70 cm ^-1为中心的六种振动模式。傅里叶变换红外 (FT-IR) 结果显示存在两个键，即 C-O 和 Hg-I。透射电子显微镜 (TEM) 结果表明，在 22.9 J/cm ²、25-75 nm 尺寸下制备的样品形成球形纳米颗粒。而用 33.1 和 43.3 J/cm ²合成的纳米颗粒分别表现出纳米棒和纳米管的形态。β-HgI ₂的暗 I-V 特性NPs/Si 异质结光电探测器显示出整流特性，结质量取决于激光能量密度，并且在 33.1 J/cm ^{2 下}制备的异质结获得了最佳结特性。HgI ₂ /p-Si 光电探测器的白光光敏度是在不同强度下在反向偏压下测量的。对于在 33.1 J/cm ^{2 下}制备的光电探测器，在 450 nm 处达到的最大响应率为 3.39A/W 。