Controllable carrier doping and transport of van der Waals heterostructures

Two-dimensional (2D) materials of wide-ranging properties can now be simply stacked together to form van der Waals (vdW) heterostructures, offering enormous research opportunities. To explore unprecedented physical properties and enable functional electronic devices, local gates are usually used to modulate carrier concentration and implement various doping profiles in the 2D vdW heterostructures. However, the fabrication of local gate nanostructures requires sophisticated fabrication procedures that degrade the device quality and lack flexibility. Recent work has demonstrated an alternative way to induce nanoscale rewritable doping patterns in vdW heterostructures without introducing impurities by optical illumination or applying an STM tip voltage pulse. In this work we further develop this simple but efficient local patterning technique and study the low-temperature transport properties of patterned vdW heterostructures. Our results demonstrate that this technique offers distinct advantages over conventional local gates, making it an ideal approach for designing and prototyping novel device concepts.