Alloyed transition metal dichalcogenides provide an opportunity for coupling band engineering with valleytronic phenomena in an atomically-thin platform. However, valley properties in alloys remain largely unexplored. We investigate the valley degree of freedom in monolayer alloys of the phase change candidate material WSe_2(1-x)Te_2x. Low temperature Raman measurements track the alloy-induced transition from the semiconducting 1H phase of WSe₂ to the semimetallic 1T_d phase of WTe₂. We correlate these observations with density functional theory calculations and identify new Raman modes from W-Te vibrations in the 1H-phase alloy. Photoluminescence measurements show ultra-low energy emission features that highlight alloy disorder arising from the large W-Te bond lengths. Interestingly, valley polarization and coherence in alloys survive at high Te compositions and are more robust against temperature than in WSe₂. These findings illustrate the persistence of valley properties in alloys with highly dissimilar parent compounds and suggest band engineering can be utilized for valleytronic devices.

合金化过渡金属二卤化物为原子薄平台中的能带工程与谷电子现象耦合提供了机会。但是，合金中的谷底性能仍未开发。我们研究相变候选材料WSe _2（1-x） Te _2x的单层合金的谷自由度。低温拉曼测量跟踪从WSE的半导体1H相中的合金诱导的过渡₂到半金属1T _d WTE的阶段₂。我们将这些观察结果与密度泛函理论计算相关联，并从1H相合金中的W-Te振动中识别出新的拉曼模式。光致发光测量显示出超低能量发射特征，突出了由大的W-Te键长度引起的合金无序。有趣的是，合金中的谷底极化和相干性在高Te成分下仍然存在，并且比WSe ₂更耐高温。这些发现说明了具有高度相似的母体化合物的合金中谷值特性的持久性，并表明能带工程可用于Valleytronic器件。