Local Interface Effects Modulate Global Charge Order and Optical Properties of 1<i>T</i>-TaS₂/1<i>H</i>-WSe₂ Heterostructures.

Abstract

1<i>T</i>-TaS₂ is a layered charge density wave (CDW) crystal exhibiting sharp phase transitions and associated resistance changes. These resistance steps could be exploited for information storage, underscoring the importance of controlling and tuning the CDW states. Given the importance of out-of-plane interactions in 1<i>T</i>-TaS₂, modulating interlayer interactions by heterostructuring is a promising method for tailoring CDW phase transitions. In this work, we investigate the optical and electronic properties of heterostructures comprising 1<i>T</i>-TaS₂ and monolayer 1<i>H</i>-WSe₂. By systematically varying the thickness of 1<i>T</i>-TaS₂ and its azimuthal alignment with 1<i>H</i>-WSe₂, we find that intrinsic moiré strain and interfacial charge transfer introduce CDW disorder in 1<i>T</i>-TaS₂ and modify the CDW ordering temperature. Furthermore, our studies reveal that the interlayer alignment impacts the exciton dynamics in 1<i>H</i>-WSe₂, indicating that heterostructuring can concurrently tailor the electronic phases in 1<i>T</i>-TaS₂ and the optical properties of 1<i>H</i>-WSe₂. This work presents a promising approach for engineering the optoelectronic behavior of heterostructures that integrate CDW materials and semiconductors.