Applying elastic deformation can tune a material’s physical properties locally and reversibly. Spatially modulated lattice deformation can create a bandgap gradient, favoring photogenerated charge separation and collection in optoelectronic devices. These advantages are hindered by the maximum elastic strain that a material can withstand before breaking. Nanomaterials derived by exfoliating transition metal dichalcogenides (TMDs) are an ideal playground for elastic deformation, as they can sustain large elastic strains, up to a few percent. However, exfoliable TMDs with highly strain-tunable properties have proven challenging for researchers to identify. We investigated 1T-ZrS₂ and 1T-ZrSe₂, exfoliable semiconductors with large bandgaps. Under compressive deformation, both TMDs dramatically change their physical properties. 1T-ZrSe₂ undergoes a reversible transformation into an exotic three-dimensional lattice, with a semiconductor-to-metal transition. In ZrS₂, the irreversible transformation between two different layered structures is accompanied by a sudden 14% bandgap reduction. These results establish that Zr-based TMDs are an optimal strain-tunable platform for spatially textured bandgaps, with a strong potential for novel optoelectronic devices and light harvesting.

中文翻译：

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分层半导体1T–ZrX ₂（X = S，Se）中通过机械变形进行结构相变和带隙控制

施加弹性变形可以局部且可逆地调整材料的物理特性。空间调制的晶格变形会产生带隙梯度，从而有利于光电器件中光生电荷的分离和收集。这些优点受到材料在断裂之前可以承受的最大弹性应变的阻碍。通过剥脱过渡金属二硫化碳（TMDs）衍生的纳米材料是弹性变形的理想场所，因为它们可以承受高达百分之几的大弹性应变。但是，事实证明，具有高度应变可调性的可剥脱TMD对研究人员来说具有挑战性。我们研究了1T-ZrS ₂和1T-ZrSe ₂，具有大带隙的可剥离半导体。在压缩变形下，两个TMD都会显着改变其物理性质。1T-ZrSe ₂经过可逆转变为奇异的三维晶格，并具有从半导体到金属的转变。在ZrS _2中，两个不同分层结构之间的不可逆转换伴随着突然的14％带隙减小。这些结果表明，基于Zr的TMD是用于空间纹理化带隙的最佳应变可调平台，在新型光电器件和光收集方面具有强大的潜力。