SEMICONDUCTOR PHOTODETECTOR WITH TRANSPARENT INTERFACE CHARGE CONTROL LAYER AND METHOD THEREOF
First Claim
1. A detection device comprising:
- a photodetector comprising a first semiconductor layer through which light first enters the photodetector;
the first semiconductor layer formed of a first semiconductor material crystal lattice which terminates at an interface;
the discontinuity of the semiconductor crystal lattice at the interface creating a first interface charge;
the first semiconductor layer being an absorption layer in which photons in a predetermined wavelength range are absorbed and create photogenerated carriers; and
a second polar semiconductor layer deposited on the crystal lattice of the first semiconductor layer, the second polar semiconductor being substantially transparent to light in the predetermined wavelength range, the second polar semiconductor layer having a total polarization different from the first semiconductor layer so that a second interface charge is induced at the interface between the first and second semiconductor layers;
the induced second interface charge reduces or substantially cancels the first interface charge;
whereby the reduction or substantial cancellation of the surface charge in the first semiconductor layer increases the collection of photogenerated carriers by the photodetector.
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Accused Products
Abstract
A detection device comprising a photodetector comprising a first semiconductor layer through which light first enters the photodetector; the first semiconductor layer to semiconductor material crystal lattice which terminates at an interface; the discontinuity of the semiconductor crystal lattice at the interface creating a first interface charge; the first semiconductor layer being an absorption layer in which photons in a predetermined wavelength range are absorbed and create photogenerated carriers; and a second polar semiconductor layer deposited on the crystal lattice of the first semiconductor layer, the second polar semiconductor being substantially transparent to light in the predetermined wavelength range, the second polar semiconductor layer having a total polarization different from the first semiconductor layer so that a second interface charge is induced at the interface between the first and second semiconductor layers; the induced second interface charge reduces or substantially cancels the first interface charge; whereby the reduction or substantial cancellation of the surface charge in the first semiconductor layer increases the collection of photogenerated carriers by the photodetector. A method of improving the quantum efficiency of a semiconductor photodetector comprising providing a semiconductor photodetector having a first layer which has a first interface through which light first enters the semiconductor photodetector; placing a layer of polar material transparent to the band of detection wavelengths that has a polarization substantially different than the polarization of the first layer such that the polarization charge induced at the interface between the layer of polar material and the first surface results in decreased interface recombination of photogenerated minority carriers and an increase in quantum efficiency of the photodetector.
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Citations
20 Claims
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1. A detection device comprising:
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a photodetector comprising a first semiconductor layer through which light first enters the photodetector;
the first semiconductor layer formed of a first semiconductor material crystal lattice which terminates at an interface;
the discontinuity of the semiconductor crystal lattice at the interface creating a first interface charge;
the first semiconductor layer being an absorption layer in which photons in a predetermined wavelength range are absorbed and create photogenerated carriers; anda second polar semiconductor layer deposited on the crystal lattice of the first semiconductor layer, the second polar semiconductor being substantially transparent to light in the predetermined wavelength range, the second polar semiconductor layer having a total polarization different from the first semiconductor layer so that a second interface charge is induced at the interface between the first and second semiconductor layers;
the induced second interface charge reduces or substantially cancels the first interface charge;whereby the reduction or substantial cancellation of the surface charge in the first semiconductor layer increases the collection of photogenerated carriers by the photodetector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A light detector comprising:
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a primary semiconductor layer comprising an optically exposed photon reception region; a secondary semiconductor layer adjacent to and having total polarization different, from the primary semiconductor layer so that an interface charge is induced at the interface between the primary and secondary semiconductor layers;
the induced charge reduces or substantially cancels the interface charge caused by the discontinuity of the semiconductor lattice of the primary semiconductor at the interface; anda photodetection element which converts the photon flux to electric current; whereby the reduction or cancellation of the interface charge in the primary semiconductor layer increases the collection of photogenerated earners generated by photons having energy larger than the bandgap of the first semiconductor layer by the photodetection element. - View Dependent Claims (17, 18)
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19. A method of improving the quantum efficiency of a semiconductor photodetector comprising:
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providing a semiconductor photodetector having a first layer which has a first interface through which light first enters the semiconductor photodetector; placing a layer of polar material transparent to the band of detection wavelengths that has a polarization substantially different than the polarization of the first layer such that the polarization charge induced at the interface between the layer Of polar material and the first surface results in decreased interface recombination of photogenerated minority carriers and an increase in quantum efficiency of the photodetector. - View Dependent Claims (20)
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Specification