We have investigated the effect of the uniaxial strain on the electrical properties of few-layer ZrSe3 devices under compressive and tensile strain, applied up to ± 0.62 % along different crystal directions. We observed that the piezoresponse, the change in resistance upon straining, of ZrSe3 strongly depends on both the direction in which electrical transport occurs and the direction in which uniaxial strain is applied. We obtained a remarkably high anisotropy in the gauge factor for a device with the transport occurring along the b-axis of the ZrSe3: GF = 68 when the strain is applied along b-axis and GF = 4 when the strain is applied along a-axis. This leads to an anisotropy ratio of almost 90 %. Devices whose transport occurs along the a-axis, on the other hand, show much lower anisotropy in the gauge factors when applying strain along different directions, leading to an anisotropy ratio of 50 %. Furthermore, performed ab-initio calculations of the strain dependent change in resistance show the same trends of anisotropy ratio as our experimental results for both of electrical transport and strain application directions, which we correlated with bandgap changes and different orbital contributions.
