We investigate the electronic and optical properties of zinc iodide (ZnI₂) under the effect of the biaxial strains. It has been emphasized that ZnI₂ monolayer is stable based on the molecular dynamics simulations, phonon dispersion curve and binding energy calculations. In the equilibrium state, the results revealed that the ZnI₂ monolayer is a semiconductor with the indirect bandgap value of 2.018 eV/2.94 eV using PBE/HSE06 methods. In addition, the ZnI₂ monolayer has appropriate band-edge positions for the oxidation and reduction reactions of water splitting at pH = 0. Besides, it is disclosed that the energy bandgap varies extremely with the influence of biaxial strain reaching about 1.631 eV with the compressive strain of −6%. Generally, the change in the bandgap is higher with the compressive strain state than that with the tensile strain state. However, all energy gaps are located in the visible region and distributed in wide range regions which can have extensive nanodevices applications. Most importantly, a remarkable enhancement in the optical properties can be perceived under the strain effect. Precisely, the absorption coefficient achieves a maximum value of 16.6 × 10⁴ cm⁻¹ at −6% within the ultraviolet range. Finally, our perusal highlights that the effect of the biaxial strain on the ZnI₂ monolayer presents effectual guidance to design highly effective optoelectronic materials for nanoscale devices.

我们研究了在双轴应变的作用下碘化锌（ZnI ₂）的电子和光学性质。已经强调，基于分子动力学模拟，声子色散曲线和结合能计算，ZnI ₂单层是稳定的。在平衡状态下，结果表明，使用PBE / HSE06方法，ZnI ₂单层是一种半导体，其间接带隙值为2.018 eV / 2.94 eV。另外，ZnI ₂在pH = 0时，单层膜具有合适的能带边缘位置用于水的氧化和还原反应。此外，据揭示，能带隙在双轴应变达到约1.631 eV且压缩应变为-6％的情况下变化极大。通常，压缩应变状态的带隙变化比拉伸应变状态的带隙变化大。然而，所有的能隙都位于可见区域并分布在宽范围的区域中，这可以具有广泛的纳米器件应用。最重要的是，在应变效应下可以感觉到光学性能的显着提高。精确地，吸收系数达到最大值16.6×10 ⁴  cm ^-1 在紫外线范围内为-6％。最后，我们的研究重点指出，双轴应变对ZnI ₂单层的影响为设计用于纳米器件的高效光电材料提供了有效的指导。