Abstract: Disclosed herein is a method and apparatus for determining time of arrival of incident photons. The time of arrival may be determined with high time accuracy based on characteristics of the rate of change of a voltage across a capacitor being charged by charge carriers generated from the incident photons.

Abstract: Disclosed herein is a radiation detector system, comprising a radiation detector, the radiation detector comprising a semiconductor substrate and a pixel array in the semiconductor substrate, wherein the pixel array comprises (a) M first-row pixels, and (b) N second-row pixels, both M and N being positive integers and greater than 1, and wherein each pixel of the N second-row pixels is larger than any pixel of the M first-row pixels in a radiation direction perpendicular to a straight line segment having a first end in a first-row end pixel of the M first-row pixels and a second end in a second-row end pixel of the M first-row pixels.

Abstract: Disclosed herein is an apparatus suitable for detecting an image, comprising: a plurality of pixels configured to generate an electric signal upon exposure to a radiation; an electronics system associated with each of the pixels, wherein the electronics system comprises a first memory on a first signal path and a second memory on a second signal path, both signal paths being between an input terminal and an output terminal of the electronics system; wherein each of the first memory and the second memory is configured to store the electric signal generated by the pixel the electronics system is associated with, configured to store the electric signal generated in another pixel, and configured to transmit the electric signal stored in the electronics system to another pixel; wherein the electronics system comprises a switch configured to select one of the signal paths.

Abstract: Disclosed herein is a radiation detector comprising: a scintillator configured to emit a second radiation upon receiving a first radiation from a pulsed radiation source, a plurality of pixels, and a controller; wherein each pixel is configured to detect the second radiation; wherein the pulsed radiation source is configured to emit the first radiation during a plurality of ON periods and configured not to emit the first radiation during a plurality of OFF periods; wherein the controller is configured to determine that the pulsed radiation source is at one of the ON periods or at one of the OFF periods; wherein the controller is configured to cause the pixels to integrate signals or not to integrate signals with determination that the radiation source is at one of the ON periods or at one of the OFF periods.

Abstract: Disclosed herein is an image sensor comprising: a first package comprising a plurality of radiation detectors mounted on a printed circuit board (PCB); wherein a dead zone of the first package does not extend between neighboring radiation detectors among the plurality of radiation detectors; wherein the radiation detectors have no guard rings or sidewall doping.

Abstract: Disclosed herein is an apparatus comprising: an array of avalanche photodiodes (APDs) or an absorption region comprising a semiconductor single crystal such as a CdZnTe single crystal or a CdTe single crystal. The apparatus may be configured to absorb radiation particles incident on an absorption region of the APDs or the semiconductor single crystal and to generate charge carriers. The apparatus may comprise an electrode comprising silver nanoparticles and being electrically connected to the absorption region of the APDs or the semiconductor single crystal. For the APDs, each of the APDs may comprise an amplification region, which may comprise a junction with an electric field in the junction. The electric field may be at a value sufficient to cause an avalanche of charge carriers entering the amplification region, but not sufficient to make the avalanche self-sustaining. The junctions of the APDs may be discrete.

Abstract: Disclosed herein is an apparatus comprising: an array of avalanche photodiodes (APDs), each of the APDs comprising an absorption region and an amplification region; wherein the absorption region is configured to generate charge carriers from a photon absorbed by the absorption region; wherein the absorption region comprises a silicon epitaxial layer; wherein the amplification region comprises a junction with an electric field in the junction; wherein the electric field is at a value sufficient to cause an avalanche of charge carriers entering the amplification region, but not sufficient to make the avalanche self-sustaining; wherein the junctions of the APDs are discrete.

Abstract: Disclosed herein is a detector, comprising: a pixel comprising a first subpixel and a second subpixel, wherein the first subpixel is configured to generate a first electrical signal upon exposure to radiation, and wherein the second subpixel is configured to generate a second electrical signal upon exposure to the radiation; wherein the detector is configured to determine a number of particles of the radiation incident on the first subpixel over a first period of time, based on the first electrical signal; wherein the detector is configured to determine an intensity of the radiation by integrating the second electrical signal over a second period of time.

Abstract: An apparatus for detecting radiation, comprising: a first radiation absorption layer configured to generate first electrical signals from a photon of the radiation absorbed by the first radiation absorption layer, wherein the first radiation absorption layer comprises a first electrode; an electronic system configured to process the first electrical signals; a counter configured to register a number of photons absorbed by the radiation absorption layer; a controller; the controller is configured to cause the number registered by the counter to increase by one; a power supply; and a communication interface configured for the electronic system to communicate with outside circuitry.

Abstract: Disclosed herein is an apparatus comprising: an X-ray absorption layer; a first electrical contact and a second electrical contact; wherein the first electrical contact and the second electrical contact respectively comprise structures extending into the X-ray absorption layer; wherein the structures of the first electrical contact and the structures of the second electrical contact do not electrically short.

Abstract: Disclosed herein is a radiation detector, comprising: a plurality of pixels, and a controller; wherein each pixel is configured to detect radiation emitted from a pulsed radiation source; wherein the pulsed radiation source is configured to emit radiation during a plurality of ON periods and configured not to emit radiation during a plurality of OFF periods; wherein the controller is configured to determine that the pulsed radiation source is at one of the ON periods or at one of the OFF periods; wherein the controller is configured to cause the pixels to integrate signals or not to integrate signals with determination that the radiation source is at one of the ON periods or at one of the OFF periods.

Abstract: An apparatus, system and method suitable for detecting X-ray are disclosed. In one example, the apparatus comprises: an X-ray absorption layer and a mask; wherein the mask comprises a first window and a second window, and a portion between the first window and the second window; wherein the first and second windows are not opaque to an incident X-ray; wherein the portion is opaque to the incident X-ray; and wherein the first and second windows are arranged such that charge carriers generated in the X-ray absorption layer by an X-ray photon propagating through the first window and charge carriers generated in the X-ray absorption layer by an X-ray photon propagating through the second window do not spatially overlap.

Abstract: Disclosed herein is a radiation detector, comprising: pixels arranged in an array, the pixels comprising peripheral pixels at a periphery of the array and interior pixels at an interior of the array, each of the pixels configured to generate an electrical signal on an electrode thereof, upon exposure to a radiation; an electronic system configured to provide first compensation to the peripheral pixels for a dark noise of the peripheral pixels and to provide second compensation to the interior pixels for a dark noise of the interior pixels, the first compensation and the second compensation being different.

Abstract: Disclosed herein is a detector, comprising: a plurality of pixels, each pixel configured to count numbers of X-ray photons incident thereon whose energy falls in a plurality of bins, within a period of time; an X-ray absorption layer; wherein the X-ray absorption layer comprises an electrical contact within each of the pixels, and a focusing electrode surrounding the electrical contact and configured to direct to the electrical contact charge carriers generated by an X-ray photon incident within confines of the focusing electrodes; and wherein the detector is configured to add the numbers of X-ray photons for the bins of the same energy range counted by all the pixels.

Abstract: Disclosed herein are various methods for making apparatuses suitable for detecting X-ray. The method may comprise bonding a plurality of chips to a first substrate, wherein the first substrate comprises a plurality of electric contacts and a plurality of vias connecting the electric contacts to a surface of the first substrate, wherein each of the chips comprises an X-ray absorption layer comprising a first electrode and a second electrode, and wherein the plurality of chips are bonded to the first substrate such that the second electrode of each of the chips is electrically connected to at least one of the electrical contacts.

Abstract: Disclosed herein is an apparatus comprising: a radiation absorption layer comprising an electrode; a counter; a controller configured to cause a number registered by the counter to change, in response to an absolute value of an electrical signal on the electrode equaling or exceeding an absolute value of a second threshold during a time delay that is started from a time at which the absolute value of the electrical signal equals or exceeds an absolute value of a first threshold.

Abstract: Disclosed herein is 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.

Abstract: Disclosed herein is a system comprising: a first X-ray detector in a first layer; a second X-ray detector in a second layer; wherein the first X-ray detector comprises a first X-ray absorption layer and a first electronics layer; wherein the second X-ray detector comprises a second X-ray absorption layer and a second electronics layer; wherein the first X-ray detector is mounted to a first surface of a first printed circuit board; wherein the second X-ray detector is mounted to a first surface of a second printed circuit board, or to a second surface of the first printed circuit board opposite to the first surface of the first printed circuit board; wherein gaps in the second X-ray absorption layer are shadowed by the first X-ray absorption layer.

Abstract: Disclosed herein is a radiation detector, comprising: a radiation absorption layer comprising an electrode; a voltage comparator that compares a voltage of the electrode to a first threshold; a counter that registers a number of photons of radiation absorbed by the radiation absorption layer; a controller; and a voltmeter. The controller is configured to start a time delay from a time at which the voltage comparator determines that an absolute value of the voltage equals or exceeds an absolute value of the first threshold. The controller is configured to cause the voltmeter to measure the voltage upon expiration of the time delay. The controller is configured to determine the number of photons by dividing the voltage measured by the voltmeter by a voltage that a single photon would have caused on the electrode. The controller can cause the number registered by the counter to increase by the number of photons.

Abstract: Disclosed herein is a radiation detector configured to absorb radiation particles incident on a semiconductor single crystal of the radiation detector and to generate positive charge carriers and negative charge carriers in the semiconductor single crystal. The semiconductor single crystal may be a cadmium zinc telluride (CdZnTe) single crystal or a cadmium telluride (CdTe) single crystal. The radiation detector comprises a first electrical contact in electrical contact with the semiconductor single crystal and a second electrical contact surrounding the first electrical contact or the semiconductor single crystal. The first electrical contact is configured to collect the negative charge carriers. The second electrical contact is configured to cause the positive charge carriers to drift out of the semiconductor single crystal.