OCTAHEDRAL PEROVSKITE MATERIALS WITH SMALL RADIUS METAL CENTER AND USES THEREOF

Abstract

Ge-centered octahedral perovskites have heretofore not been achievable due to collapse of the perovskite structure into non-octahedral units due to a lack of B site support from the small-radius Ge atom, which breaks Goldschmidt’s rules for constructing octahedral perovskites. To overcome this shortcoming, a strategy was developed to form a strong cage with the A sites in which the octahedron is forced to remain intact. Strong intermolecular interaction between the organic A site cations were used to stabilize the symmetric Ge octahedral perovskite beyond the Goldschmidt’s rules. The molecules used based on Y-PMA (Y: F, Cl, Br, I) that facilitated strong halogen bonding to form the cage around the octahedral. Octahedral Ge perovskites exhibit a direct bandgap in contrast to the indirect bandgap of non-octahedral Ge perovskites are demonstrated. In addition, the octahedral Ge perovskite exhibited a dramatic increase in the carrier mobility. A photodetector made with the stabilized octahedral perovskite material exhibited a vastly better responsivity than non-octahedral Ge perovskites.

Description

Claims

1. A 2D metal halide perovskite material having the Formula (I): wherein A has the formula: wherein Y is F, Br, Cl or I;each of Z1 to Z4 is independently selected from CH or N;B is Ge, Cu, Ga or Sb; andX is Cl, Br, or I.

2. The perovskite material of claim 1, wherein A has the formula: wherein Y is F, Br, Cl or l.

3. The perovskite material of claim 1, wherein A has the formula: wherein Y is Fl, Br, Cl or l.

4. The perovskite material of claim 3, wherein B is Ge.

5. A semi-2D metal halide perovskite material having the Formula (II): wherein A has the formula: wherein n is 1 to 12;Y is F, Br, Cl or I;each of Z1 to Z4 is independently selected from CH or N;A′ is Cs+, NH3+, CH2NH3+ or CHNH2NH3+;B is Ge, Cu, Ga or Sb; andX is Cl, Br or I.

6. The perovskite material of claim 5, wherein A has the formula: wherein Y is F, Br, Cl or l.

7. The perovskite material of claim 5, wherein A has the formula: wherein Y is Fl, Br, Cl or l.

8. The perovskite material of claim 7, wherein A′ is Cs.

9. The perovskite material of claim 8, wherein B is Ge.

10. An optoelectronic device comprising a perovskite material as defined in claim 1, wherein the optoelectronic device is selected from a sensor, a photodetector, a light emitting diode, an electro-optic modulator and a solar cell.

11. An optoelectronic device comprising a perovskite material as defined in claim 4, wherein the optoelectronic device is selected from a sensor, a photodetector, a light emitting diode, an electro-optic modulator and a solar cell.

12. An optoelectronic device comprising a perovskite material as defined in claim 5, wherein the optoelectronic device is selected from a sensor, a photodetector, a light emitting diode, an electro-optic modulator and a solar cell.

13. An optoelectronic device comprising a perovskite material as defined in claim 9, wherein the optoelectronic device is selected from a sensor, a photodetector, a light emitting diode, an electro-optic modulator and a solar cell.