Engineered band gaps

Patent metadata

Field	Value
Publication number	US-9484489-B2
Application number	US-201514818035-A
Country	US
Kind code	B2
Filing date	Aug 4, 2015
Priority date	Aug 5, 2014
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

An optoelectronic device as well as its methods of use and manufacture are disclosed. In one embodiment, an optoelectronic device includes first and second semiconducting atomically thin layers with corresponding first and second lattice directions. The first and second semiconducting atomically thin layers are located proximate to each other, and an angular difference between the first lattice direction and the second lattice direction is between about 0.000001° and 0.5°, or about 0.000001° and 0.5° deviant from of a Vicnal angle of the first and second semiconducting atomically thin layers. Alternatively, or in addition to the above, the first and second semiconducting atomically thin layers may form a Moiré superlattice of exciton funnels with a period between about 50 nm to 3 cm. The optoelectronic device may also include charge carrier conductors in electrical communication with the semiconducting atomically thin layers to either inject or extract charge carriers.

First claim

What is claimed is:

1. An optoelectronic device comprising:
a first semiconducting atomically thin layer having a first lattice direction;
a second semiconducting atomically thin layer having a second lattice direction, wherein the second semiconducting atomically thin layer is proximate the first semiconducting atomically thin layer, and wherein an angular difference between the first lattice direction and the second lattice direction is between about 0.000001° and 0.5°, or about 0.000001° and 0.5° of a Vicnal angle of the first and second semiconducting atomically thin layers;
a first charge carrier conductor in electrical communication with the first semiconducting atomically thin layer; and
a second charge carrier conductor in electrical communication with the second semiconducting atomically thin layer.

2. The optoelectronic device of claim 1 , wherein the first semiconducting atomically thin layer and the second semiconducting atomically thin layer are the same material and the first lattice direction and the second lattice direction are the same.

3. The optoelectronic device of claim 1 , wherein the first semiconducting atomically thin layer and the second semiconducting atomically thin layer are single crystals.

4. The optoelectronic device of claim 1 , wherein the first semiconducting atomically thin layer and the second semiconducting atomically thin layer are monolayers.

5. The optoelectronic device of claim 1 , further comprising one or more protective layers disposed between the first charge carrier conductor and the first semiconducting atomically thin layer and/or the second charge carrier conductor and the second semiconducting atomically thin layer.

6. The optoelectronic device of claim 5 , wherein the one or more protective layers include one or more openings to provide electrical contact between the first charge carrier conductor and the first semiconducting atomically thin layer and/or between the second charge carrier conductor and the second semiconducting atomically thin layer.

7. The optoelectronic device of claim 5 , further comprising a compressive element constructed and arranged to apply between about 1 GPa and 3 GPa normal to the first and second semiconducting atomically thin layers.

8. The optoelectronic device of claim 1 , further comprising a capacitor constructed and arranged to apply an electric field with a magnitude between about 0.5×10 9 V/m and 3×10 9 V/m normal to the first and second atomically thin layers.

9. The optoelectronic device of claim 1 , wherein the first charge carrier conductor and the second charge carrier conductor are aligned.

10. The optoelectronic device of claim 1 , further comprising a third charge carrier conductor in electrical communication with the first semiconducting atomically thin layer and a fourth charge carrier conductor in electrical communication with the second semiconducting atomically thin layer.

11. The optoelectronic device of claim 10 , wherein a distance between the first and third charge carrier conductors and/or between the second and fourth charge carrier conductors is less than or equal to a relaxation distance of an electron hole pair within the first and second atomically thin layers.

12. The optoelectronic device of claim 1 , wherein the first semiconducting atomically thin layer and the second semiconducting atomically thin layer comprise at least one of carbon/boron nitride, gallium(II) sulfide, gallium(II) selenide, gallium(II) telluride, graphitic carbon nitride, hexagonal boron nitride, carbon nitride, phosphorene, and a dichalcogenide.

13. The optoelectronic device of claim 1 , wherein the optoelectronic device is a light emitting diode, a solar cell, a photodetector, or an exciton laser.

14. An optoelectronic device comprising:
a first semiconducting atomically thin layer;
a second semiconducting atomically thin layer proximate the first semiconducting atomically thin layer, wherein the first and second semiconducting atomically thin layers form a Moiré superlattice of exciton funnels with a period between about 50 nm to 3 cm;
a first charge carrier conductor in electrical communication with the first semiconducting atomically thin layer; and
a second charge carrier conductor in electrical communication with the second semiconducting atomically thin layer.

15. The optoelectronic device of claim 14 , wherein the first semiconducting atomically thin layer and the second semiconducting atomically thin layer are the same material.

16. The optoelectronic device of claim 14 , wherein the first semiconducting atomically thin layer and the second semiconducting atomically thin layer are single crystals.

17. The optoelectronic device of claim 14 , wherein the first semiconducting atomically thin layer and the second semiconducting atomically thin layer are monolayers.

18. The optoelectronic device of claim 14 , further comprising one or more protective layers disposed between the first charge carrier conductor and the first semiconducting atomically thin layer and/or between the second charge carrier conductor and the second semiconducting atomically thin layer.

19. The optoelectronic device of claim 18 , wherein the one or more protective layers include one or more openings to provide electrical contact between the first charge carrier conductor and the first semiconducting atomically thin layer and/or the second charge carrier conductor and the second semiconducting atomically thin layer.

20. The optoelectronic device of claim 18 , further comprising a compressive element constructed and arranged to apply between about 1 GPa and 3 GPa normal to the first and second semiconducting atomically thin layers.

21. The optoelectronic device of claim 14 , further comprising a capacitor constructed and arranged to apply an electric field with a magnitude between about 0.5×10 9 V/m and 3×10 9 V/m normal to the first and second atomically thin layers.

22. The optoelectronic device of claim 14 , wherein the first charge carrier conductor and the second charge carrier conductor are aligned.

23. The optoelectronic device of claim 14 , further comprising a third charge carrier conductor in electrical communication with the first semiconducting atomically thin layer and a fourth charge carrier conductor in electrical communication with the second semiconducting atomically thin layer.

24. The optoelectronic device of claim 23 , wherein a distance between the first and third charge carrier conductors and/or between the second and fourth charge carrier conductors is less than or equal to a relaxation distance of an electron hole pair within the first and second semiconducting atomically thin layers.

25. The optoelectronic device of claim 14 , wherein the first semiconducting atomically thin layer and the second semiconducting atomically thin layer comprise at least one of carbon/boron nitride, gallium(II) sulfide, gallium(II) selenide, gallium(II) telluride, graphitic carbon nitride, hexagonal boron nitride, carbon nitride, phosphorene, and a dichalcogenide.

26. The optoelectronic device of claim 14 , wherein the optoelectronic device is a light emitting diode, a solar cell, a photodetector, or an exciton laser.

Assignees

• Massachusetts Inst Technology

Inventors

• Li Ju
• Qian Xiaofeng
• Wu Menghao

Classifications

• H10P14/3466

  Crystal orientation · CPC title

• H10P14/3436

  being chalcogenide semiconductor materials not being oxides, e.g. ternary compounds · CPC title

• H01L31/109

  Electricity · mapped topic

• H01L29/045

  Electricity · mapped topic

• H01L33/002 Primary

  Electricity · mapped topic