Direct radiation converter, radiation detector, medical apparatus and method for producing a direct radiation converter
A direct radiation converter is disclosed which includes a radiation detection material having an anode side and a cathode side in which the radiation detection material has a doping profile running in the anode-side to cathode-side direction. A radiation detector is further disclosed having such a direct radiation converter and having an anode array and a cathode array, and optionally having evaluation electronics for reading out a detector signal, as well as a medical apparatus having such a radiation detector. Also described is a method for producing a direct radiation converter which includes incorporating into a radiation detection material a doping profile running in the anode-side to cathode-side direction.
1. A direct radiation converter comprising: a radiation detection material including an anode side and a cathode side, wherein the radiation detection material includes incorporated doping agents and has a doping profile running in the anode-side to cathode-side direction, wherein at least one of a dopant concentration and a doping component only varies substantially continuously from at least one of the anode side and the cathode side to the other of the anode side and the cathode side.
2. The direct radiation converter as claimed in claim 1 , wherein the radiation detection material includes additional doping agents on the cathode side such that the doping profile comprises an increased p-type conduction on the cathode side.
3. The direct radiation converter as claimed in claim 1 , wherein the radiation detection material includes additional doping agents on the anode side such that the doping profile comprises increased n-type conduction on the anode side.
4. The direct radiation converter as claimed in claim 1 , wherein the radiation detection material is constructed from a semiconductor compound on the basis of a homogeneous base conduction and the doping profile is implemented thereon by way of additional doping on at least one of the anode side and the cathode side.
5. The direct radiation converter as claimed in claim 1 , wherein the doping profile varies from the anode side toward the cathode side at least in sections essentially continuously.
6. The direct radiation converter as claimed in claim 1 , wherein the doping profile has discontinuities from the anode side toward the cathode side.
7. The direct radiation converter as claimed in claim 1 , wherein the radiation detection material includes semiconductor compounds.
8. The direct radiation converter as claimed in claim 1 , wherein the radiation detection material is constructed from II-VI semiconductor compounds and the doping agents for the II-VI semiconductor compounds are elements from group I or group V or a mixture thereof; or elements from group VII or group III or a mixture thereof.
9. The direct radiation converter as claimed in claim 1 , wherein the radiation detection material is constructed from III-V semiconductor compounds and the doping agents for III-V semiconductor compounds are elements from group II, group IV, subgroups thereof or a mixture thereof; or elements from group IV or group VI or a mixture thereof.
10. A radiation detector comprising:
the direct radiation converter as claimed in claim 1 ;
an anode arrangement; and
a cathode arrangement.
11. A medical apparatus comprising the radiation detector as claimed in claim 10 .
12. The medical apparatus as claimed in claim 11 , further comprising an X-ray system, a gamma ray system, a PET system, a CT system or a SPECT system.
13. The radiation detector as claimed in claim 10 , further comprising:
evaluation electronics that receives a detector signal produced in the direct radiation converter.
14. The direct radiation converter as claimed in claim 4 , wherein the radiation detection material is constructed from a semiconductor compound on the basis of a p-type conduction or n-type conduction, and the doping profile is implemented thereon by way of additional doping on at least one of the anode side and the cathode side.
15. The direct radiation converter as claimed in claim 5 , wherein the doping profile varies from the anode side toward the cathode side at least in sections essentially exponentially or sigmoidally.
16. The direct radiation converter as claimed in claim 7 , wherein the radiation detection material includes semiconductor compounds selected from the group consisting of Cd x Zn 1-x Te y Se 1-y (where 0≦x≦1; 0≦y≦1) or Cd x Mn 1-x Te y Se 1-y (where 0≦x≦1; 0≦y≦1), Ga x In 1-x Sb y As 1-y (where 0≦x≦1; 0≦y≦1), Ga x In 1-x Sb y P 1-y (where 0≦x≦1; 0≦y≦1), Al x In 1-x Sb y As 1-y (where 0≦x≦1; 0≦y≦1), Al x In 1-x Sb y P 1-y (where 0≦x≦1; 0≦y≦1), Ga x In 1-x Sb y N 1-y (where 0≦x≦1; 0≦y≦1), Ga x In 1-x N y P 1-y (where 0≦x≦1; 0≦y≦1).
17. The direct radiation converter as claimed in claim 8 , wherein the elements from group I or group V or a mixture of said elements are Li, Na, K, Rb, Cs or N, P, As, Sb, Bi, respectively, and wherein elements from group VII or group III or a mixture of said elements are F, Cl, Br, I or B, Al, Ga, In, Tl, respectively.
18. The direct radiation converter as claimed in claim 9 , wherein the elements from group II, group IV, the subgroups or a mixture of said elements are Be, Mg or C, Si, Ge, Sn, Pb or Zn, Cd, Hg, Cr, V, Ti, respectively, and wherein elements from group IV or group VI or a mixture of said elements are C, Si, Ge, Sn, Pb or O, S, Se, Te, respectively.