Patent Number: 
Section: claims

1. An apparatus suitable for detecting X-ray, comprising:an X-ray absorption layer comprising an electrode;an electronics layer, the electronics layer comprising: a substrate having a first surface and a second surface, an electronics system in or on the substrate, an electric contact on the first surface, and a first via extending from the first surface toward the second surface;wherein the electrode is electrically connected to the electric contact;wherein the electronics system comprises a controller connected in series with and between the electric contact and the first via. 2. The apparatus of claim 1, wherein the electronics system comprises a transmission line on the second surface and the first via is electrically connected to the transmission line. 3. The apparatus of claim 1,wherein the electronics system comprises:a first voltage comparator configured to compare a voltage of the electrode to a first threshold;a second voltage comparator configured to compare the voltage to a second threshold;a counter configured to register a number of X-ray photons reaching the X-ray absorption layer;wherein the controller is configured to start a time delay from a time at which the first voltage comparator determines that an absolute value of the voltage equals or exceeds an absolute value of the first threshold;wherein the controller is configured to cause the number registered by the counter to increase by one, if the second voltage comparator determines that an absolute value of the voltage equals or exceeds an absolute value of the second threshold. 4. The apparatus of claim 1, further comprising a capacitor module electrically connected to the electrode, wherein the capacitor module is configured to collect charge carriers from the electrode. 5. The apparatus of claim 3, wherein the controller is configured to activate the second voltage comparator at a beginning or expiration of the time delay. 6. The apparatus of claim 3, further comprising a voltmeter, wherein the controller is configured to cause the voltmeter to measure the voltage upon expiration of the time delay. 7. The apparatus of claim 6, wherein the controller is configured to determine an X-ray photon energy based on a value of the voltage measured upon expiration of the time delay. 8. The apparatus of claim 1, wherein the controller is configured to connect the electrode to an electrical ground. 9. The apparatus of claim 3, wherein a rate of change of the voltage is substantially zero at expiration of the time delay. 10. The apparatus of claim 3, wherein a rate of change of the voltage is substantially non-zero at expiration of the time delay. 11. The apparatus of claim 3, wherein the controller is configured to deactivate the first voltage comparator at a beginning of the time delay. 12. The apparatus of claim 3, wherein the controller is configured to deactivate the second voltage comparator at expiration of the time delay or at a time when the second voltage comparator determines that the absolute value of the voltage equals or exceeds the absolute value of the second threshold, or a time in between. 13. The apparatus of claim 1, wherein the X-ray absorption layer comprises a diode. 14. The apparatus of claim 1, wherein the X-ray absorption layer comprises silicon, germanium, GaAs, CdTe, CdZnTe, or a combination thereof. 15. The apparatus of claim 1, wherein the apparatus does not comprise a scintillator. 16. The apparatus of claim 1, wherein the apparatus comprises an array of pixels. 17. The apparatus of claim 1, wherein the electronics layer further comprises a peripheral circuit arranged on the first surface. 18. The apparatus of claim 1, wherein the electronics layer further comprises a peripheral circuit arranged between the first surface and the second surface and the first via is connected in series with and between the controller and the peripheral circuit. 19. The apparatus of claim 18, wherein the electronics system comprises a transmission line on the second surface; wherein the electronics layer comprises a second via connected in series with and between the peripheral circuit and the transmission line. 20. A system comprising the apparatus of claim 1 and an X-ray source. 21. A system comprising a stack of two layers, each layer comprising a plurality of the apparatuses of claim 1 arranged in an array, wherein the arrays of the two layers are staggered relative to one another.