SnS has recently been shown to possess unique valleytronic capability with a large polarization degree, where non-degenerate valleys can be accessed using linearly polarized light, bestowed upon by the unique anisotropy and wavefunction symmetry. It is thus of utmost importance to demonstrate the extension of such effects for the IV–VI system in general, thereby elucidating the generality and tunability of such valleytronics. We show the highly tunable valleytronics via gradual compositional control of the tin(II) sulfo-selenide (SnSxSe1−x) alloy system with excellent retainment of symmetry-determined selection rules. We show the presence of both ΓY and ΓX valleys in all alloy compositions via selectivity in absorption and emission of linearly polarized light by optical reflection (R)/transmission (T) and photoluminescence measurements and tuned the bandgaps of the valleys within a range of 1.28 eV–1.05 eV and 1.48 eV–1.24 eV, respectively. This simultaneous tuning of non-degenerate valleys agrees well with theoretical calculations. We then fitted the bandgap values in compositional space, obtaining bowing parameters as a useful database. We further demonstrated the feasibility of using IV–VI valleytronics systems in general by elucidating the retainment of strong polarization degrees of as high as 91% across all compositions. The generalization of such purely symmetry-dependent valleytronics also opens up opportunities for the discovery of more multi-functional materials.SnS has recently been shown to possess unique valleytronic capability with a large polarization degree, where non-degenerate valleys can be accessed using linearly polarized light, bestowed upon by the unique anisotropy and wavefunction symmetry. It is thus of utmost importance to demonstrate the extension of such effects for the IV–VI system in general, thereby elucidating the generality and tunability of such valleytronics. We show the highly tunable valleytronics via gradual compositional control of the tin(II) sulfo-selenide (SnSxSe1−x) alloy system with excellent retainment of symmetry-determined selection rules. We show the presence of both ΓY and ΓX valleys in all alloy compositions via selectivity in absorption and emission of linearly polarized light by optical reflection (R)/transmission (T) and photoluminescence measurements and tuned the bandgaps of the valleys within a range of 1.28 eV–1.05 eV and 1.48 eV–1.24 eV, respectively. This simultaneous tuning of non-degenerate valleys agrees well wi...

中文翻译：

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在 SnSxSe1−x 模型系统中具有保持对称性的高偏振度的可调谐谷电子学

最近已证明 SnS 具有独特的谷电子能力和大偏振度，其中可以使用线偏振光访问非简并谷，这是由独特的各向异性和波函数对称性赋予的。因此，证明 IV-VI 系统的这种效应的扩展是最重要的，从而阐明这种谷电子学的通用性和可调性。我们通过锡 (II) 磺基硒化物 (SnSxSe1-x) 合金系统的渐进成分控制展示了高度可调的谷电子学，并很好地保留了对称性决定的选择规则。我们通过光学反射 (R)/透射 (T) 和光致发光测量对线性偏振光的吸收和发射选择性显示了所有合金成分中存在 ΓY 和 ΓX 谷，并将谷的带隙调整到 1.28 的范围内分别为 eV–1.05 eV 和 1.48 eV–1.24 eV。这种非退化谷的同时调谐与理论计算非常吻合。然后我们在成分空间中拟合带隙值，获得弯曲参数作为有用的数据库。我们通过阐明在所有组合物中保留高达 91% 的强偏振度，进一步证明了一般使用 IV-VI 谷电子学系统的可行性。这种纯粹依赖对称性的谷电子学的推广也为发现更多多功能材料开辟了机会。 最近已证明 SnS 具有独特的谷电子学能力和大极化度，其中可以使用线性极化来访问非简并谷光，赋予其独特的各向异性和波函数对称性。因此，证明 IV-VI 系统的这种效应的扩展是最重要的，从而阐明这种谷电子学的通用性和可调性。我们通过锡 (II) 磺基硒化物 (SnSxSe1-x) 合金系统的渐进成分控制展示了高度可调的谷电子学，并很好地保留了对称性决定的选择规则。我们通过光学反射 (R)/透射 (T) 和光致发光测量对线性偏振光的吸收和发射选择性显示了所有合金成分中存在 ΓY 和 ΓX 谷，并将谷的带隙调整到 1.28 的范围内分别为 eV–1.05 eV 和 1.48 eV–1.24 eV。这种非退化谷的同时调谐与...