P-type transparent conducting nickel oxide alloys
Disclosed herein is the formation of p-type transparent conducting oxides (TCO) having a structure of Mg x Ni 1-x O or Zn x Ni 1-x O. These structures disrupt the two-dimensional confinement of individual holes (the dominant charge carrier transport mechanism in pure NiO) creating three-dimensional hole transport by providing pathways for hole transfer in directions that are unfavorable in pure NiO. Forming these structures preserves NiO's transparency to visible light since the band gaps do not deviate significantly from that of pure NiO. Furthermore, forming Mg x Ni 1-x O or Zn x Ni 1-x O does not lead to hole trapping on O ions adjacent to Zn and Mg ions. The formation of these alloys will lead to creation of three-dimensional hole transport and improve NiO's conductivity for use as p-type TCO, without adversely affecting the favorable properties of pure NiO.
1. A composition of matter with a rock salt structure comprising a substitutional alloy having the formula:
Mg x Ni 1-x O, where M is Mg or Zn, and 0<x<1,
wherein spin configurations in the presence of a hole include singly occupied O 2p orbitals and filled Mg 2p or Zn 3d orbitals.
2. The composition of matter according to claim 1 , wherein 0.2≤x≤0.3.
3. The composition of matter according to claim 1 , wherein x is 0.25.
4. The composition of matter according to claim 1 , wherein a quasiparticle gap is between 3.3 and 4.4.
5. A device comprising:
A first layer, the first layer comprising a p-type semiconductor substitutional alloy having a rock salt structure, the p-type semiconductor alloy comprising the formula: Mg x Ni 1-x O, where M is Mg or Zn, and 0<x<1,
wherein spin configurations of the p-type semiconductor alloy in the presence of a hole include singly occupied O 2p orbitals and filled Mg 2p or Zn 3d orbitals.
6. The device according to claim 5 , wherein 0.2≤x≤0.3.
7. The device according to claim 5 , wherein x is 0.25.
8. The device according to claim 5 , wherein the device further comprises:
an electrolyte;
dye molecules; and
a layer comprising a transparent n-type semiconductor.
9. The device according to claim 8 , wherein the transparent n-type semiconductor comprises titanium dioxide.
10. The device according to claim 5 , wherein the first layer has a thickness between about 500 nanometers and about 100 micrometers.
11. The device according to claim 5 , wherein the device further comprises:
an electron acceptor layer;
an electron donor layer; and
a conducting layer.
12. The device according to claim 11 , wherein the electron acceptor layer, the electron donor layer, or both also act as a light absorber.
13. The device according to claim 5 , wherein the device further comprises:
at least one layer selected from the group consisting of an electron injection layer (EIL) and a hole injection layer (HIL);
a light absorbing layer; and
a conducting layer.
14. The device according to claim 5 , wherein the device further comprises:
an amorphous silicon layer; and
a conducting layer.
15. The device according to claim 5 , wherein the first layer is adapted to function as part of a solar cell or a solar energy conversion device.
16. The device according to claim 5 , wherein a quasiparticle gap of the p-type semiconductor alloy is between 3.3 and 4.4.