Description:
Background
This invention shows that crystallographically dissimilar and incommensurate atomically-thin MoS2 and Bi2Se3 layers can form rotationally-aligned stacks with long-range crystallographic order. Our theory predicts and experiments reveal striking electronic and optical changes when Bi2Se3 is stacked layer-by-layer on monolayer MoS2, including the formation of an indirect bandgap and 100% photoluminescence (PL) suppression, tunable transmittance-edge (1.1 eV®0.75 eV), suppressed Raman, and wide-band evolution of spectral transmittance. The range of edge energies is highly attractive for beyond-silicon electronics and optoelectronics, especially for telecommunications wavelengths that require active electronics at the 1550 nm (0.8 eV) standard. 
Tunable absorbance, reflectance, and photoemission in these crystals make them potentially important for various photovoltaic and photodetection applications in the visible range. Disrupting the rotational alignment using a focused laser results in a spectacular reversal of PL, Raman, and transmittance, demonstrating for the first time that in-situ manipulation of interfaces can enable “reconfigurable” 2D materials. Northeastern University researchers have utilized this laser-writing approach to demonstrate 2D heterocrystals with patterns, arrays, and optical information (bit) storage abilities. It is possible to conceive various photonic, plasmonic and optoelectronic applications that may benefit from such highly precise optical arrays and circuit-drawing in an atomically-thin material.
 
Technology Overview
Northeastern University researchers present a new type of vertical stacking between 2D crystals of molybdenum disulfide (MoS2) tri-layers (TLs) and bismuth selenide (Bi2Se3) quintuple layers (QLs). This includes a process for the controlled synthesis of a uniquely new class of vertically stacked 2D heterocrystals with a novel “switchable” PL, and widely-tunable optical transmittance values and transmittance edges. The range of edge energies is highly attractive for beyond-silicon electronics and optoelectronics, especially for telecommunications wavelengths that require active electronics at the 1550 nm (0.8 eV) standard. Tunable absorbance, reflectance, and photoemission in these crystals make them potentially important for various photovoltaic and photodetection applications in the visible range. 
Also presented a novel laser-induced reversal of the electronic and optical properties, especially the striking manner in which the PL can be reversed, and its sharp vs. broadband nature can be tuned.
Atomically thin materials are stack-able with a particular alignment. 
 
Benefits
- Atomically thin materials (< 10 nm)
- Reconfigurable by laser with sub-micron resolution
- Synthesized by chemical vapor deposition (CVD)
 
Applications
- Optical communication
- Opto-Electronic applications like flexible electronics
- Light-emitting
- Optical sensing
 
Opportunity
- License
- Partnering
- Research collaboration
 
Patent Information:
For Information, Contact:
Mark Saulich
Associate Director of Commercialization
Northeastern University
m.saulich@northeastern.edu
Inventors:
Anthony Vargas
Fangze Liu
Christopher Lane
Daniel Rubin
Arun Bansil
Swastik Kar
Zachariah Hennighausen
Keywords:
Data Storage
Devices
Electronics
Energy Technology
Materials
Memory
Optoelectronics