X-ray detector
View Patent ↗An X-ray detector for detecting X rays includes a semiconductor for generating electric charges therein upon X-ray incidence, and electrodes formed on opposite sides of the semiconductor for application of a predetermined bias voltage. The semiconductor is amorphous selenium (a-Se) doped with a predetermined quantity of an alkali metal.
1. An X-ray detector for detecting X rays, comprising:
a semiconductor for generating electric charges therein upon X-ray incidence;
electrodes formed on opposite sides of said semiconductor for application of a predetermined bias voltage;
a first carrier selection layer formed on said semiconductor at a side of a positive one of said electrodes, that is at a side of an electrode having a higher potential, for restricting an injection of holes; and
a second carrier selection layer formed on said semiconductor at a side of a negative one of said electrodes, that is at a side of an electrode having a lower potential, for restricting an injection of electrons;
wherein said semiconductor is amorphous selenium (a-Se) doped with a predetermined quantity of an alkali metal or alkaline earth metal in a quantity ranging from 0.01 to 10 ppm.
2. An X-ray detector as defined in claim 1 , wherein one of said electrodes formed at an X-ray incidence side is a positive one of said electrodes to which the bias voltage is applied to increase potential.
3. An X-ray detector as defined in claim 2 , wherein the quantity of the alkali metal or alkaline earth metal doped is in a range of 0.05 to 2 ppm.
4. An X-ray detector as defined in claim 2 , wherein said alkali metal or alkaline earth metal is one of Li, Na, K, and Ca.
5. An X-ray detector as defined in claim 2 , wherein said semi-conductor is formed on a TFT substrate having thin film transistor switches, charge storing capacitors and one of said electrodes.
6. An X-ray detector as defined in claim 1 , wherein the quantity of the alkali metal or alkaline earth metal doped is in a range of 0.05 to 2 ppm.
7. An X-ray detector as defined in claim 1 . wherein said alkali metal or alkaline earth metal is one of Li, Na, K, and Ca.
8. An X-ray detector as defined in claim 1 , wherein said semi-conductor is formed on a TFT substrate having thin film transistor switches, charge storing capacitors and one of said electrodes.
9. An X-ray detector for detecting X rays, comprising:
a semiconductor for generating electric charges therein upon X-ray incidence;
electrodes formed on opposite sides of said semiconductor for application of a predetermined bias voltage;
a first carrier selection layer formed on said semiconductor at a side of a positive one of said electrodes, that is at a side of an electrode having a higher potential, for restricting an injection of holes;
wherein said semiconductor is amorphous selenium (a-Se) doped with a predetermined quantity of an alkali metal or alkaline earth metal in a quantity ranging from 0.01 to 10 ppm.