Fine-grain pyroelectric detector material and method
AssigneeTexas Instruments Incorporated
InventorBernard M. Kulwicki
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Abstract
An improved pyroelectric material comprises a polycrystalline material doped with at least one donor element such that the polycrystalline material has a grain size less than 10 .mu.m (or 5 .mu.m) and a Figure of Merit greater than 90 nC/(cm.sup.2* K). In the preferred embodiments the polycrystalline material is barium strontium titanate or calcium-substituted barium strontium titanate. The donor element may be Nb, Ta, Bi, Sb, Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er or a combination thereof. The material may additionally be doped with an accepter such as Co, Cu, Fe, Mn, Ru, Al, Ga, Mg, Sc, K, Na, U, In, Mg, Ni, Yb or a combination thereof to control the resistivity. Other structures and methods are also disclosed.
Claims10
A structure for detecting energy in the infrared spectral range comprising:
- detection circuitry formed in a semiconductor layer;
- a thermal isolation mesa formed on a surface of said semiconductor layer;
- a ceramic pixel comprising polycrystalline barium strontium titanate doped with at least one donor element such that said barium strontium titanate has a grain size less than 10 .mu.m and a Figure of Merit greater than 90 nC/(cm.sup.2* K);
- a conductive contact formed on a first surface of said ceramic pixel, said contact coupling said pixel to said detection circuitry;
- and
- an absorbing layer for absorbing said infrared energy thereby heating said ceramic pixel.
Dependencies are inferred from the claim text.