Semiconductor suitable for use in photoanode
A composition of matter includes an n-type semiconductor. At least a portion of the semiconductor has the crystal structure of the chemical compound represented by FeWO 4 . The portion of the semiconductor having the crystal structure of FeWO 4 includes iron and tungsten. A photoanode can have a light-absorbing layer that includes or consists of the semiconductor. A solar fuels generator can include the photoanode.
1. A composition of matter, comprising:
an n-type semiconductor,
at least a portion of the semiconductor having the crystal structure of the chemical compound represented by FeWO 4 ; and
the portion of the semiconductor having the crystal structure of FeWO 4 including Fe, O, Bi and W.
2. The composition of claim 1 , where in the semiconductor consists of the O, the Fe, the Bi, and the W.
3. The composition of claim 1 , wherein the semiconductor is represented by Fe 1-x W x O v +y(BiO z ) wherein:
0<x<1;
0≤y<1;
0<v<2; and
1≤z≤2.
4. The composition of claim 3 , wherein the semiconductor includes a first crystal phase having Fe 1-x W x O v arranged in the crystal structure of FeWO 4 .
5. The composition of claim 4 , wherein the semiconductor includes a second crystal phase having BiO z arranged in the crystal structure of Bi 2 O 3 .
6. The composition of claim 4 , wherein the semiconductor includes the second crystal phase on an exterior surface of the first crystal phase.
7. The composition of claim 4 , wherein the semiconductor includes a second crystal phase having the crystal structure of Fe 2 O 3 .
8. The composition of claim 1 , wherein the semiconductor has a turn-on voltage above 0.0 V vs RHE and below 0.45 V vs RHE and a direct band gap energy above 1 eV and below 2.4 eV.
9. A photoanode having a light-absorbing layer that includes the semiconductor of claim 1 .
10. An electro-oxidation system that includes the photoanode of claim 9 .
11. A solar fuels generator that includes the photoanode of claim 9 .
12. A composition of matter includes a semiconductor represented by Fe 1-x W x O v +y(BiO z ) wherein:
0<x<1,
0≤y<1,
0<v<2, and
1≤z≤2; and
at least a portion of the semiconductor is arranged in the crystal structure of FeWO 4 .
13. The composition of claim 12 , wherein the portion of the semiconductor with the crystal structure of FeWO 4 has a chemical composition represented by Fe 1-x W x O v .
14. The composition of claim 13 , wherein y>0.
15. The composition of claim 13 , wherein at least a portion of the semiconductor is arranged in the crystal structure of Bi 2 O 3 .
16. The composition of claim 12 , wherein y>0.
17. The composition of claim 12 , wherein at least a portion of the semiconductor is arranged in the crystal structure of Fe 2 O 3 .