Information storage by changing the valence state of a semi-conductor crystal

Claim 2

An information storage system comprising: a. a semiconductor crystal having deep-level donors and multivalent particles incorporated therein; b. means for selectively transferring electrons and holes between said donors and said multi-valent particles, thereby causing reciprocal changes in the valence states of the respective donors and multi-valent particles; and c. means for determining the respective valence states of said particles and of said donors, including means for measuring the characteristic radiation absorption bands of the respective donors and multi-valent particles, without destruction of the stored information.

Claim 3

The information storage system according to claim 1 wherein said semiconductor crystal comprises a Group IIB-VIA compound or a Group III-VA compound doped with a transition metal selected from the group consisting of titanium, vananium, chromium, manganese, iron, cobalt, nickel, and copper.

Claim 4

The information storage stystem according to claim 1 wherein said semiconductor is zinc sulfide, said deep-level donor is Fe2 and said multi-valent particle is Ni2 .

Claim 5

The information storage system according to claim 1 wherein said means for selectively transferring electrons and holes between said donors and said multi-valent particles includes means for directing electromagnetic radiation of a first predetermined wavelength through said crystal to transfer holes from said donors to said particles; and means for directing electromagnetic radiation of a second determined wavelength through said crystal to transfer holes from said multi-valent particles to said donors; and wherein said means for determining the valence state of respective donors and particles includes means for directing electromagnetic radiation of a third predetermined wavelength through said crystal whereby information stored is read-out without destruction of the information stored.

Claim 6

The information storage system according to claim 4 wherein said means for directing electromagnetic radiation of a second predetermined wavelength through said crystal includes means sequentially directing said electromagnetic radiation of said second wavelength through different selected portions of said semiconductor crystal.

Claim 7

The information storage system according to claim 4 wherein the semiconductor crystal is selected from ZnS, ZnSe, ZnTe, CdS, CdSe, and CdTe.

Claim 8

The information storage system according to claim 4 wherein said semiconductor crystal is zinc sulfide, sand deep-level donor is Fe2 , said multi-valent particle is Ni2 ; wherein said first predetermined wavelength is about 5800 A.; wherein said second predetermined wavelength is about 11000 A.; and wherein said third predetermined wavelength is about 8000 A.

Claim 9

The information storage system according to claim 4 further including means for selectively changing the valence states of said donors and said particles to their original valence states including means for directing electromagnetic radiation of a fourth predetermined wavelength through said crystal whereby information stored in said system is erased.

Claim 10

The information storage system according to claim 8 wherein said fourth predetermined wavelength is less than any of said first, second and third predetermined wavelengths.