SnS holds great promise in optoelectronics, especially in photovoltaic devices, due to its exceptional intrinsic electronic properties and optimal optical absorption. However, its prospective applications are often limited by structural instability or oxidation, leading to internal or external defect states. This study proposes a mixed-phase SnS/h-BN heterostructure to enhance chemical and thermal stability while preserving the intrinsic optoelectronic properties of SnS. High negative binding energy and ab initio molecular dynamics simulations confirm the structural and thermal stability of the heterostructure up to 600 K. The heterostructure exhibits a type-I band alignment with an indirect density functional theory (DFT) band gap of 1.38 eV, corrected to 2.20 eV using Green's function with screened Coulomb potential (GW) calculations. The vertical intralayer electric field, resulting from non-uniformity in charge dynamics within the heterostructure, influences the SnS bound excitons, causing reduction in their binding energies. The weakly bound excitons indicate effective charge separation, charge transport augmentation, and a prolonged recombination lifetime. The interface effectively combines the excellent light-harvesting capabilities of SnS with the remarkable stability of h-BN, retaining the desirable optoelectronic properties of SnS while offering enhanced charge transport and stability.

中文翻译：

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通过混合相异质结构工程增强 SnS 的光电性能


SnS 因其卓越的固有电子特性和最佳的光吸收，在光电子学中，尤其是在光伏器件中具有很大的前景。然而，其潜在应用往往受到结构不稳定或氧化的限制，导致内部或外部缺陷状态。本研究提出了一种混合相 SnS/h-BN 异质结构，以增强化学和热稳定性，同时保留 SnS 的固有光电特性。高负结合能和从头开始的分子动力学模拟证实了异质结构在 600 K 以下的结构和热稳定性。异质结构表现出 I 型带对准，间接密度泛函理论 （DFT） 带隙为 1.38 eV，使用格林函数和筛选库仑电位 （GW） 计算校正为 2.20 eV。由异质结构内电荷动力学的不均匀性产生的垂直层内电场会影响 SnS 结合激子，导致其结合能降低。弱结合激子表明有效的电荷分离、电荷传输增强和延长的复合寿命。该界面有效地结合了 SnS 出色的光捕获能力和 h-BN 的卓越稳定性，保留了 SnS 理想的光电特性，同时提供了增强的电荷传输和稳定性。