TITLE : Van der Waals Hetero-structures for Orbital Gating in Photo-transistors and Electronic Spectroscopies

ABSTRACT :

Each atomic layer in van der Waals hetero-structures possesses a distinct electronic band structure
that can be manipulated for unique device operations. The subtle but critical band coupling between the atomic
layers, varied by the momentum (valley) of electrons and external electric fields in device operation, has not

yet been presented or applied to designing original devices with the full potential of van der Waals hetero-
structures. In this talk, I will introduce interlayer coupling spectroscopy at the device-scale based on the

negligible quantum capacitance of two-dimensional semiconductors in lattice-orientation- tuned, resonant
tunneling transistors (Figure 1.). The effective band structures of the mono-, bi-, and quadri-layer of MoS2
and

WSe2
, modulated by the orientation- and external electric field-dependent interlayer coupling in device
operations, could be demonstrated by the new conceptual spectroscopy overcoming the limitations of the

former optical, photoemission, and tunneling spectroscopy [1]. Based on the vertical hetero-junction, single-
defect resonant transistors [2], and novel orbital-gating phototransistors [3] could be developed.

ABOUT THE SPEAKER :

MEETING DETAILS :

Joining Link: events/SPS Seminar_HeejunYang-April11-2023..pdf

Speaker: Prof. Heejun Yang

Venue: Online

Date and Time: April 11th, 2023, 12 pm