Space-charge-free semiconductor and method
A semiconductor having a an n-type material and a p-type material, wherein the n-type material and p-type material are joined to form a space-charge-free p-n junction. The energy of the Fermi-level of the n-type material is equal to the energy of the Fermi-level of the p-type material. This allows for the pre-alignment of the Fermi-levels of the n-type and the p-type materials. The semiconductor has minimal or no g-r noise. The semiconductor can be operated at T BLIP in the range of about 220° to about 240° K.
1. A semiconductor comprising:
an n-type material having a characteristic Fermi level;
a p-type material having a characteristic Fermi level; and
an intrinsic material disposed between the n-type material and the p-type material,
wherein the n-type material, the intrinsic material, and the p-type material are joined together at a p-i-n junction;
further wherein the characteristic Fermi-level of the n-type material is equal to the characteristic Fermi-level of the p-type material prior to joining the n-type and p-type materials.
2. The semiconductor of claim 1 , wherein the energy levels of the valence band and the conduction band in the n-type material is lower than the energy levels of the valance band and the conduction band in the p-type material.
3. The semiconductor of claim 1 , wherein the semiconductor is a photodetector having a T BLIP operating range that is equal to or greater than about 220° K.
4. The semiconductor of claim 1 , wherein the n-type material comprises InAs, InSb or HgCdTe.
5. The semiconductor of claim 1 , wherein the n-type material comprises InAs and the p-type material comprises Al .0.79 Ga 0.21 As 0.14 Sb 0.86 .
6. The semiconductor of claim 1 wherein the energy level of the intrinsic material valence band is not lower than the energy level of the n-type material valance band.
7. A short-wave detector, mid-wave detector, long-wave detector, very long-wave detector, type II (strained) superlattice infrared detector, or photovoltaic device comprising the semiconductor of claim 1 .
8. A thermal imager comprising:
a semiconductor, wherein the semiconductor comprises an n-type material having a characteristic Fermi level and a p-type material having a characteristic Fermi level, wherein the n-type material and p-type material are joined together at a p-i-n junction and wherein the Fermi-level of the n-type material is equal to the Fermi-level of the p-type material prior to joining the n-type and p-type materials.
9. A method of making a semiconductor comprising:
selecting an n-type material having a first characteristic Fermi level;
selecting a p-type material having a second characteristic Fermi level, wherein the second characteristic Fermi level is equal to the first characteristic Fermi level;
providing an intrinsic layer between the n-type material and the p-type material; and
joining the n-type material to the p-type material to create a space-charge-free p-i-n junction.
10. The method of claim 9 , wherein the n-type material comprises InAs, InSb or HgCdTe.
11. The method of claim 10 , wherein the p-type material comprises Al z Ga 1-z As 1-y Sb y , wherein z is about 0.7 to about 0.9 and y is about 0.85 to about 0.87.
12. A method of making a semiconductor, comprising:
selecting a p-type material having a first characteristic Fermi level;
selecting an n-type material having a second characteristic Fermi level,
wherein the second Fermi level is equal to the first Fermi level prior to joining the p-and n-type materials; and
joining the p-type material and the n-type materials to create a space-charge-free p-i-n junction.