TWI768872B - Single photon emission device and light-emitting device - Google Patents

Abstract

A single photon emission device and a light-emitting device are provided, and the single photon emission device includes a stacked structure, a source and a drain, and an external driving circuit. The source and the drain are disposed on opposite sides of the stacked structure, respectively. The stacked structure includes a single electron transistor (SET) as an electron source or a single hole transistor (SHT) as a hole source, tunnel layers, and a recombination region. The external driving circuit is configured to output a driving signal. According to the driving signal, the single electron in the SET and/or the single hole in the SHT are recombined in the recombination region for emitting a single photon, and the recombination region is a quantum dot, an undoped direct-gap semiconductor layer, or a anti-state doped region carrier pool.

Description

Single-photon light-emitting element and light-emitting device

The present invention relates to a single-photon light-emitting device (Single Photon Emission Device, SPED), and more particularly, to a single-photon light-emitting device and a light-emitting device composed of a single exciton device (Single Exciton Device, SED).

Quantum communication is one of the main research and application directions of quantum technology. The most ideal light source for quantum communication is a single photon source. To achieve single-photon luminescence, a specific two-level system must be manipulated "individually" so that only one photon is produced per external trigger. The single-photon gun candidate systems currently under study include semiconductor quantum dots, mesoscopic quantum wells, single-molecule luminescence, single-atom luminescence, and color-center luminescence in diamonds.

However, no practical, controllable, electrically excited single-photon source has yet been developed.

The present invention provides a single-photon light-emitting element, which can achieve a controllable single-photon source.

The present invention further provides a light-emitting device, which can suppress unnecessary and unused spontaneous emission and increase the required spontaneous emission.

A single-photon light-emitting element of the present invention includes a stack structure, a source electrode and a drain electrode, and an external driving circuit. The source electrode and the drain electrode are respectively disposed on opposite sides of the stack structure. The stacked structure includes a single electron quantum dot, a first tunnel layer, a single electron gate structure, a single hole quantum dot, a second tunnel layer and a single hole gate structure. The first tunneling layer completely covers the single-electron quantum dots, and the single-electron gate structure completely surrounds the single-electron quantum dots and is isolated from the single-electron quantum dots through the first tunneling layer. A single hole quantum dot is adjacent to the single electron quantum dot, the second tunneling layer completely covers the single hole quantum dot, and the single hole gate structure completely surrounds the single hole quantum dot The dots are isolated from the single-hole quantum dots through the second tunneling layer. The external drive circuit is configured to output a drive signal, and according to the drive signal, control the single-electron tunneling of the single-electron quantum dot to inject into the single-hole quantum dot, so that the electron hole is injected into the single-hole quantum dot. Recombination emits a single photon; or, controlling the single-hole tunneling of the single-hole quantum dot to inject the single-electron quantum dot, so that the electron-hole recombination at the single-electron quantum dot emits a single photon.

In an embodiment of the present invention, the number of the single-electron quantum dots is multiple, the number of the single-hole quantum dots is single, and the multiple single-electron quantum dots and the single single-hole quantum dot are Points are stacked on top of each other.

In an embodiment of the present invention, the number of the single-electron quantum dots is single, the number of the single-hole quantum dots is multiple, and the single single-electron quantum dot and the multiple single-hole quantum dots Points are stacked on top of each other.

In an embodiment of the present invention, the number of the single-electron quantum dots is multiple, the number of the single-hole quantum dots is multiple, and the multiple single-electron quantum dots and the multiple single-hole quantum dots Points are horizontally adjacent to each other.

In an embodiment of the present invention, the number of the single-electron quantum dots is multiple, the number of the single-hole quantum dots is multiple, and the multiple single-electron quantum dots and the multiple single-hole quantum dots Dots are configured in pairs up and down.

Another single-photon light-emitting element of the present invention includes a stack structure, a source electrode and a drain electrode, and an external driving circuit. The source electrode and the drain electrode are respectively disposed on opposite sides of the stack structure. The stacked structure includes a single-electron quantum dot, a first tunneling layer, a single-electron gate structure, a single-hole quantum dot, a second tunneling layer, a single-hole gate structure, and an undoped direct energy gap semiconductor layer. The first tunneling layer completely covers the single-electron quantum dots, and the single-electron gate structure completely surrounds the single-electron quantum dots and is isolated from the single-electron quantum dots through the first tunneling layer. The second tunneling layer completely covers the single-hole quantum dot, and the single-hole gate structure completely surrounds the single-hole quantum dot and passes through the second tunneling layer, and the single-hole quantum dot is connected to the single-hole quantum dot. isolated. The undoped direct energy gap semiconductor layer is interposed between the single-electron quantum dot and the single-hole quantum dot, and through the first and second tunneling layers, the single-electron quantum dot and the single-hole quantum dot are respectively connected with the single-electron quantum dot and the single-hole quantum dot. points are isolated. The external drive circuit is configured to output a drive signal, and control the single electron of the single electron quantum dot according to the drive signal. The electrons and the single hole of the single hole quantum dot are tunneled and injected into the undoped direct energy gap semiconductor layer, so that the electron holes recombine in the undoped direct energy gap semiconductor layer to emit a single photon.

In another embodiment of the present invention, the single-photon light-emitting element may further include a control gate structure and an insulating layer. The control gate structure completely surrounds the undoped direct energy gap semiconductor layer, and an insulating layer is located between the control gate structure and the undoped direct energy gap semiconductor layer.

In another embodiment of the present invention, the undoped direct energy gap semiconductor layer is a quantum dot layer or a quantum well layer.

In the above embodiments of the present invention, the single-electron quantum dots and the single-hole quantum dots may be of the same material or different materials.

Yet another single-photon light-emitting element of the present invention includes: a stack structure, a source electrode and a drain electrode, and an external driving circuit. The source electrode and the drain electrode are respectively disposed on opposite sides of the stack structure. The stacked structure includes quantum dots, a tunnel layer, a control gate structure, and an anti-state doped region carrier pool. The quantum dots are single-electron quantum dots or single-hole quantum dots, and the tunneling layer completely covers the quantum dots. The control gate structure completely surrounds the quantum dots and is isolated from the quantum dots through the tunneling layer. The anti-state carrier pool is adjacent to the quantum dots and has an opposite conductive state with the quantum dots, and is isolated from the quantum dots through the tunneling layer. The external driving circuit is configured to output a driving signal, and according to the driving signal, control the single electron or single hole of the quantum dot to be injected into the reverse state carrier pool, so that the electron hole is in the reverse state The carrier pool recombines to emit a single photon.

In yet another embodiment of the present invention, the quantum dots are single-electron quantum dots, and the anti-state carrier pool is a P-type carrier pool.

In yet another embodiment of the present invention, the quantum dots are single-hole quantum dots, and the anti-state carrier pool is an N-type carrier pool.

In yet another embodiment of the present invention, the inverse carrier pool is a one-dimensional or two-dimensional or three-dimensional semiconductor structure.

In yet another embodiment of the present invention, the one-dimensional semiconductor structure includes a nanowire, the two-dimensional semiconductor structure includes a quantum well, and the three-dimensional semiconductor structure includes a bulk. .

In various embodiments of the present invention, the single-electron quantum dots are N-type direct energy gap semiconductor quantum dots or metal quantum dots.

In various embodiments of the present invention, the single-hole quantum dots are P-type direct energy gap semiconductor quantum dots.

Still another light-emitting device of the present invention includes: a structure with an optical resonant cavity and the above-mentioned single-photon light-emitting element, and the single-photon light-emitting element is arranged in the structure with an optical resonant cavity.

In yet another embodiment of the present invention, the structure with the optical resonant cavity includes a micropillar structure, a photonic crystal structure or a microdisk structure.

In yet another embodiment of the present invention, the above-mentioned light emitting device may further include a Bragg reflector (DBR) outer cavity for condensing light.

Based on the above, the present invention uses a single-electron transistor (SET) or a single-hole The quantum dot structure of the crystal (SHT) can be combined with an external circuit to achieve a controllable single-photon luminescence mechanism, and the electron-hole recombination center of the single-photon light-emitting element of the present invention can be controlled in a preset area, so it is expected to achieve single-photon luminescence. In addition, the single-photon light-emitting element of the present invention is arranged in a structure with an optical resonant cavity, so the emission efficiency of the quantum dots can be significantly improved.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

10, 10', 10", 10 ''' , 50, 50', 80, SPED: single photon light-emitting element

90: Lighting device

100, 500, 800: Stacked structure

102a: source

102b: Drain

104: External drive circuit

106: Single Electron Quantum Dots

108: The first tunneling layer

110: Single Electron Gate Structure

112: Single-hole quantum dots

114: Second Tunneling Layer

116: Single-hole gate structure

502, i: undoped direct energy gap semiconductor layer

504, 806: Control gate structure

506: Insulation layer

802: Quantum Dots

804: Tunneling Layer

808: Anti-state carrier pool

900: Structures with Optical Resonant Cavities

C_spacer, C1_spacer, C2_spacer, C3_spacer, Cn_spacer: capacitance generated by the tunneling layer between SET and SHT

C_SET_spacer: The capacitance generated by the tunneling layer between the SET and the undoped direct-gap semiconductor layer

C_SHT_spacer: The capacitance generated by the tunneling layer between the SHT and the undoped direct-gap semiconductor layer

Cd_SHT: capacitance generated by the tunneling layer between SHT and drain

Cg_SET, Cg_SET1, Cg_SET2, Cg_SET3, Cg_SETn: Capacitance due to tunneling layer between SET and single electron gate structure

Cg_SHT: The capacitance generated by the tunneling layer between the SHT and the single-hole gate structure

Cs_SET, Cs_SET1, Cs_SET2, Cs_SET3, Cs_SETn: capacitance generated by the tunneling layer between SET and source

SET, SET#1, SET#2, SET#3, SET#n: positions of single electron quantum dots

SHT: Location of single-hole quantum dots

Vd: drain voltage

Vg_SET, Vg_SET1, Vg_SET2, Vg_SET3, Vg_SETn: single electron gate voltage

Vg_SHT: single-hole gate voltage

Vs, Vs1, Vs2, Vs3, Vsn: source voltage

FIG. 1 is an exploded schematic view of a single-photon light-emitting element according to the first embodiment of the present invention.

FIG. 2 is an energy band diagram of the single-photon light-emitting element of FIG. 1 .

FIG. 3 is an equivalent circuit diagram of the single-photon light-emitting element of FIG. 1 .

4A is an exploded schematic view of a single-photon light-emitting element of another example of the first embodiment.

FIG. 4B is an equivalent circuit diagram of the single-photon light-emitting element of FIG. 4A .

4C is an exploded schematic view of the single-photon light-emitting element of still another example of the first embodiment.

FIG. 4D is an exploded schematic view of the single-photon light-emitting element of still another example of the first embodiment.

FIG. 5 is a schematic diagram of a single-photon light-emitting element according to the second embodiment of the present invention. Solution diagram.

FIG. 6 is an equivalent circuit diagram of the single-photon light-emitting element of FIG. 5 .

7 is an exploded schematic view of a single-photon light-emitting element of another example of the second embodiment.

FIG. 8 is an exploded schematic view of a single-photon light-emitting element according to the third embodiment of the present invention.

FIG. 9 is an exploded schematic view of a light emitting device according to a fourth embodiment of the present invention.

The following examples are described in detail with the accompanying drawings, but the provided examples are not intended to limit the scope of the present invention. In addition, the drawings are for illustrative purposes only and are not drawn in full scale. In order to facilitate understanding, the same elements in the following description will be described with the same symbols.

In addition, the terms such as "include", "include", "have", etc. used in the text are all open-ended terms, that is, "including but not limited to".

It will be understood that, although the terms "first," "second," "third," etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, and/or or parts shall not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, "a first element", "component", "region", "layer", or "section" discussed below can be termed a second element, component, region domains, layers or sections without departing from the teachings herein.

In addition, the directional terms mentioned in the text, such as "up", "down", etc., are only used to refer to the direction of the drawings, and are not used to limit the present invention.

FIG. 1 is an exploded schematic view of a single-photon light-emitting element according to the first embodiment of the present invention.

Referring to FIG. 1 , a single-photon light-emitting device 10 includes a stack structure 100 , a source electrode 102 a and a drain electrode 102 b , and an external driving circuit 104 . The source electrode 102 a and the drain electrode 102 b are respectively disposed on opposite sides of the stack structure 100 . It should be noted that although the structural decomposition schematic diagrams attached to the description are all represented in the shape of a cylinder and a disk, they are only used to express relative positions in space, and do not limit the actual shape of the single-photon light-emitting element of the present invention, and Vertical or horizontal or other orientation is not restricted. The stack structure 100 in the first embodiment includes a single electron quantum dot 106, a first tunneling layer 108, a single electron gate structure 110, a single hole quantum dot 112, and a second tunneling layer 114 and a single-hole gate structure 116 . The first tunneling layer 108 completely covers the single-electron quantum dots 106 , the single-electron gate structure 110 completely surrounds the single-electron quantum dots 106 and passes through the first tunneling layer 108 , and the single-electron quantum dots 106 are isolated. The single hole quantum dot 112 is adjacent to the single electron quantum dot 106 , the second tunneling layer 114 completely covers the single hole quantum dot 112 , and the single hole gate structure 116 completely surrounds the single hole quantum dot 112 . The hole quantum dots 112 are isolated from the single hole quantum dots 112 through the second tunneling layer 114 . Therefore, the single-photon light-emitting element 10 of the present invention is a gate-all-around (GAA) structure, and needs to pass through the carrier transmission path. Tunnel through a thin insulating layer. For example, the thickness of the first tunneling layer 108 and the thickness of the second tunneling layer 114 are each below about 60 Å, such as a thickness of 30 Å to 60 Å.

The external driving circuit 104 is configured to output a driving signal, and according to the driving signal, control the single-electron tunneling of the single-electron quantum dot 106 to inject into the single-hole quantum dot 112, so that the electron hole is injected into the single-electron quantum dot 112. The hole quantum dots 112 recombine to emit a single photon; or, control the single-hole tunneling of the single-hole quantum dots 112 to inject into the single-electron quantum dots 106 , so that the electron-holes recombine in the single-electron quantum dots 106 to emit a single photon.

In this embodiment, the single-hole quantum dot 112 is used as the hole source, and the single electron transistor (SET) is used as the electron source, and the single-electron tunneling is injected into the single-hole quantum dot 112; or vice versa, The single-electron quantum dot 106 is used as the electron source, and the single-hole transistor (SHT) is used as the hole source, and the single-hole tunnel is injected into the single-electron quantum dot 106, so that the electron-hole recombination emits a single photon , the recombination center is one of the single-hole quantum dot 112 and the single-electron quantum dot 106 .

The structure of SET referred to here is a quantum dot covered by an insulating layer (the first tunneling layer 108 ) and has a quantum confinement effect, which is called a central island (single electron quantum dot 106 ). The quantum dots are n-type direct-gap semiconductors. The SET is electrically a three-terminal device: the carrier tunnels from the source 102a into the central island, and then tunnels out from the central island into the drain 102b, and the potential of the central island is controlled by the gate (the single-electron gate structure 110 ). ) controlled.

Here, the SHT structure is defined by the insulating layer (the second tunneling layer 114). The coated quantum dots also have quantum confinement effect and are called central islands (single-hole quantum dots 112 ), wherein the central island of the quantum dots of the SHT is a P-type direct energy gap semiconductor quantum dot. The SHT is electrically a three-terminal device: the carriers tunnel from the source 102a into the central island, and then tunnel from the central island to the drain 102b, and the potential of the central island is controlled by the gate (single-hole gate structure 116) controlled.

其中，I(t)為光場強度隨時間的變化函數。 Theoretically, the calibration of a single-photon signal source is described by the second-order intensity correlation coefficient of the light field:

Among them, I(t) is the variation function of light field intensity with time.

The ideal single-photon source is when only one photon is emitted at a time, and the probability of two photons arriving at the same time is zero, that is, g ⁽²⁾ (0)=0. In the present invention, the signal of the external driving circuit 104 can be used to control the circuit to be turned on or off to adjust the potential of the SET/SHT in the single-photon light-emitting element 10 to determine the emission frequency of the single-photon.

The mode of the single photon light-emitting element 10 is an artificial single exciton diode (Single Exciton Device, SED) structure. The traditional definition of excitons is that they are related by the Coulomb force between electrons and holes; as for the single-electron-single-hole quantum dot light-emitting element of the first embodiment, the correlation of the recombination emission of photons is given by The external driving circuit 104 is controlled (switching speed) through the above-mentioned control gate, so it can also be regarded as a single exciton transistor. With the inherent quantum dot structure of SET or SHT, the high density of state (DOS) increases the internal quantum efficiency (IQE) to reduce nonradiative recombination. In short, the structure of the single-photon light-emitting element 10 and Quantum dot light-emitting element with single electron-single hole function.

In this embodiment, the single-electron quantum dots 106 and the single-hole quantum dots 112 can be made of the same material or different materials. If the single-electron quantum dots 106 and the single-hole quantum dots 112 are made of the same material, the single-photon light-emitting device 10 can be regarded as a homogenous SED, for example, the single-electron quantum dots 106 and the single-hole quantum dots 112 are both. GaAs; if the single-electron quantum dots 106 and the single-hole quantum dots 112 are made of different materials, the single-photon light-emitting device 10 can be regarded as a heterogeneous single-exciton device (Heterogeneous SED), for example, the single-electron quantum dots 106 are silicon, single-hole quantum dots Dot 112 is GaAs; single electron quantum dot 106 is SiGe, and single hole quantum dot 112 is GaAs.

In one embodiment, the fabrication of the above-mentioned stacked structure 100 is, for example, firstly forming AlGaAs/n-SiGe (N-type direct energy gap semiconductor)/AlGaAs/p-GaAs (P-type direct energy gap semiconductor) on a silicon substrate (not shown) in sequence. energy gap semiconductor)/AlGaAs, and then a wet oxygen process is performed, and only AlGaAs is oxidized to Al ₂ O ₃ as a tunneling layer. However, the present invention is not limited to this, and the single-photon light-emitting element 10 can also be fabricated by using the prior art.

FIG. 2 is an energy band diagram of the single-photon light-emitting element of FIG. 1 , wherein corresponding structures and layers are shown. In FIG. 2 , SET represents the position of the single-electron quantum dot 106 , SHT represents the position of the single-hole quantum dot 112 , and the first and second tunneling layers 108 and 114 are generally oxides and thus have high energy barriers. In the case of an electric field supplied by an external driving circuit, the energy band of the high energy barrier region is tilted, which drives single electrons or single holes to tunnel.

FIG. 3 is an equivalent circuit diagram of the single-photon light-emitting element of FIG. 1 . In Figure 3, C_spacer refers to the capacitance generated by the tunneling layer between SET and SHT, Cs_SET refers to the capacitance generated by the tunneling layer between SET and source, Cd_SHT refers to the capacitance generated by the tunneling layer between SHT and drain, and Cg_SET refers to the tunneling layer generated between SET and the single-electron gate structure Cg_SHT refers to the capacitance generated by the tunneling layer between the SHT and the single-hole gate structure, Vs is the source voltage, Vd is the drain voltage, Vg_SET refers to the single-electron gate voltage, and Vg_SHT refers to the single-electron gate voltage. hole gate voltage.

FIG. 4A is an exploded schematic view of the single-photon light-emitting element of another example of the first embodiment, in which some components are omitted to highlight the difference from FIG. 1 .

Referring to FIG. 4A , the number of single-electron quantum dots 106 in the single-photon light-emitting element 10 ′ is multiple (eg, n), the number of single-hole quantum dots 112 is single, and the single-electron quantum dot 106 is associated with a single single-hole quantum dot 106 . The hole quantum dots 112 are stacked on top of each other. The single-electron quantum dots 106 and the single-hole quantum dots 112 are also completely covered by the first and second tunneling layers 108 and 114 , and other components not shown are the same as in FIG. 1 .

4B is an equivalent circuit diagram of the single-photon light-emitting element of FIG. 4A , wherein SET1 , SET2 . . . SETn represent the first, second . A controllable single exciton array.

In another embodiment, the number of single-electron quantum dots 106 may be single, the number of single-hole quantum dots 112 may be multiple, and the single-electron quantum dots 106 and the single-hole quantum dots 112 may be stacked on top of each other configuration.

FIG. 4C is an exploded schematic view of the single-photon light-emitting element according to another example of the first embodiment, in which some components are omitted to highlight the difference from FIG. 1 .

Referring to FIG. 4C , the number of single-electron quantum dots 106 in the single-photon light-emitting element 10 ″ is multiple, and the number of single-hole quantum dots 112 is also multiple, and they are horizontal to each other Adjacent to another geometric arrangement of a plurality of controllable single exciton arrays.

FIG. 4D is an exploded schematic view of the single-photon light-emitting element according to still another example of the first embodiment, in which some components are omitted to highlight the difference from FIG. 1 .

Referring to FIG. 4D , the number of single-electron quantum dots 106 and single-hole quantum dots 112 in the single-photon light-emitting element 10 ″ is multiple, and the top and bottom are arranged in pairs to form a plurality of controllable single-exciton arrays. Another geometric arrangement.

5 is an exploded schematic view of a single-photon light-emitting element according to the second embodiment of the present invention, wherein the same element symbols as in the first embodiment are used to represent the same or similar components, and the content of the same or similar components can also be referred to The content of the first embodiment will not be repeated here.

Referring to FIG. 5 , the difference between this embodiment and the first embodiment is that the stack structure 500 of the single-photon light-emitting element 50 further has an undoped (undoped) direct energy gap semiconductor layer 502 , wherein the undoped direct energy The gap semiconductor layer 502 is a quantum dot layer or a quantum well layer. The undoped direct energy gap semiconductor layer 502 is interposed between the single-electron quantum dots 106 and the single-hole quantum dots 112, and is connected to the single-electron quantum dots through the first and second tunneling layers 108 and 114, respectively. Dot 106 and single-hole quantum dot 112 are isolated. The driving signal output by the external driving circuit 104 can control the single electron of the single electron quantum dot 106 and the single hole of the single hole quantum dot 112 to tunnel into the undoped direct energy gap semiconductor layer 502, so that the electron hole can be injected into the undoped direct energy gap semiconductor layer 502. A single photon is recombined at the undoped direct-gap semiconductor layer 502 . The material of the undoped direct energy gap semiconductor layer 502 may be the same or different from that of the single electron quantum dots 106 , and the material of the undoped direct energy gap semiconductor layer 502 may also be the same or different from that of the single hole quantum dots 112 .

FIG. 6 is an equivalent circuit diagram of the single-photon light-emitting element of FIG. 5 . The difference from FIG. 3 is that there is an i representing an undoped direct energy gap semiconductor layer between SET and SHT, and C_SET_spacer refers to SET and undoped semiconductor layers. C_SHT_spacer refers to the capacitance generated by the tunneling layer between the SHT and the undoped direct energy gap semiconductor layer.

7 is an exploded schematic view of a single-photon light-emitting element according to another example of the second embodiment, wherein the same element symbols as in FIG. 5 are used to represent the same or similar components, and the content of the same or similar components can also refer to the content of FIG. 5 ,No longer.

Referring to FIG. 7 , the single-photon light-emitting element 50' may further include a control gate structure 504 and an insulating layer 506. The control gate structure 504 completely surrounds the undoped direct gap semiconductor layer 502 , and the insulating layer 506 is located between the control gate structure 504 and the undoped direct gap semiconductor layer 502 . The control gate structure 504 may increase the degree of control freedom.

8 is an exploded schematic view of a single-photon light-emitting element according to the third embodiment of the present invention, wherein the same element symbols as in the first embodiment are used to represent the same or similar components, and the content of the same or similar components can also be referred to The content of the first embodiment will not be repeated here.

Referring to FIG. 8 , the difference between this embodiment and the first embodiment is that the stack structure 800 of the single-photon light-emitting element 80 includes: quantum dots 802 , a tunneling layer 804 , a control gate structure 806 and an anti-state carrier pool (anti -state doped region carrier pool) 808. The tunneling layer 804 completely covers the quantum dots 802, and the control gate structure 806 completely surrounds the quantum dots 802 and passes through the tunneling layer 804 to communicate with the quantum dots. 802 is isolated.

The anti-state carrier pool 808 is adjacent to the quantum dot 802 and is in an opposite conductive state to the quantum dot 802 , and is isolated from the quantum dot 802 through the tunneling layer 804 . The inversion carrier pool 808 is, for example, a one-dimensional or two-dimensional or three-dimensional semiconductor structure. The one-dimensional semiconductor structure includes a nanowire, the two-dimensional semiconductor structure includes a quantum well, and the three-dimensional semiconductor structure includes a bulk.

Please continue to refer to FIG. 8 , in this embodiment, single-electron quantum dots are used as an example, wherein the single-electron quantum dots are N-type direct energy gap semiconductor quantum dots or metal quantum dots, and the anti-state carrier pool 808 is a P-type carrier pool. The driving signal output by the external driving circuit 104 can control the single electron tunneling injection of the quantum dots 802 into the inversion carrier pool 808 through the source electrode 102a, the drain electrode 102b and the control gate structure 806, so that the The electron-hole recombination in the anti-state (P-type) carrier pool 808 emits a single photon.

In another embodiment, if the quantum dot 802 is a single-hole quantum dot, the anti-state carrier pool is an N-type carrier pool, and the positions of the source electrode and the drain electrode are also interchanged. The single-hole quantum dots may be P-type direct energy gap semiconductor quantum dots. Once the external driving circuit 104 outputs the driving signal, the single hole tunneling injection of the quantum dot 802 can be controlled through the source (the part indicated by 102a ), the drain (the part indicated by 102b ) and the control gate structure 806 . A carrier pool (anti-state carrier pool 808) is used to make electron holes recombine in the N-type carrier pool to emit single photons.

FIG. 9 is an exploded schematic view of a light emitting device according to a fourth embodiment of the present invention.

Referring to FIG. 9, the light-emitting device 90 of the fourth embodiment includes an optical common The structure 900 of the resonance cavity and the single-photon light-emitting element SPED, and the single-photon light-emitting element SPED is arranged in the structure 900 having the optical resonance cavity. The single-photon light-emitting element SPED may employ any of the elements proposed in the first to third embodiments.

For the single-photon light-emitting element SPED, its main light-emitting form is mainly spontaneous emission. In order to greatly improve its efficiency, it is necessary to suppress the unnecessary and unused spontaneous emission, and to increase the required spontaneous emission. The reason for the formation of spontaneous emission is that the electrons return from the excited state to the ground state, and couple with the unoccupied optical modes in the form of photons to emit photons, and the probability of returning from the excited state to the ground state is related to the photon energy state. The density (photonic density of state) is related to the electric field strength and position, so the present invention controls the spontaneous emission through the characteristics of the photonic energy gap of the photonic crystal, and can create a point defect in the photonic crystal, at the position of the defect due to the effect of the photonic energy gap A wavelength-level resonant cavity is formed. In the photonic crystal resonant cavity, the limitation of light energy in the horizontal direction is the photon energy gap, while in the vertical direction, the condition of total reflection is used, and the loss of light energy is mainly contributed by the vertical direction. Since the photonic crystal resonant cavity has the characteristics of high Q-factor and ultra-small modal volume (small Vm), the light-emitting device 90 of the fourth embodiment is expected to have an ultra-high Q/Vm value. Electron-light interactions (quantum electro-dynamics) can be observed when Q/Vm is large enough. Designing a photonic crystal resonator with high quality factor and ultra-small modal volume can suppress excess and unused spontaneous emission and increase the required spontaneous emission. Because increasing the Q-factor of a certain frequency is increasing the number of photon modes at that frequency; and decreasing Vm is increasing the strength of the electric field.

Therefore, in FIG. 9, the structure 900 with the optical resonant cavity is a photonic crystal structure. However, the present invention is not limited to this. Types of semiconductor microresonators also include micropillar structures and microdisk structures. The common feature of these semiconductor micro-resonators is that they can form very small modal volumes, about V ₀ ~(λ/n) ³ (where n is the refractive index of the semiconductor), and the quality factor Q can be as high as Q>10 ⁴ . The modal volume of the semiconductor micro-resonator is much smaller than V ₀ <<1μm ³ , and the transition dipole moment of the semiconductor is usually larger than that of the atom, so it is sufficient to achieve the condition of strong coupling between SPED and the resonator.

In addition, the light emitting device 90 may further include a Bragg reflector (DBR) outer cavity (not shown) surrounding the structure 900 having the optical resonant cavity for concentrating light. The DBR outer cavity is, for example, an elliptical reflection cavity, but this component can also be omitted in the present invention. When the emitted single-photon energy and polarization are matched with the optical resonant cavity, the emission efficiency of the single-photon light-emitting element SPED can be significantly improved.

To sum up, the present invention utilizes a single-hole transistor (SHT) as a hole source, and a single-electron transistor (SET) as an electron source to inject single-electron tunneling into a direct-energy-gap single-hole transistor, Or conversely, the single-hole tunneling is injected into the direct energy gap single-electron transistor, so that the electron-hole recombination emits a single photon, and the recombination center is in one of the SET or SHT. Another mode of the present invention is that SET and SHT respectively inject electrons and holes into a recombination region of an undoped direct energy gap semiconductor layer, this region may have an additional control gate to adjust the potential, and recombination emits light in this region photon. Another mode of the present invention is to use only one of SET or SHT as the recombination region, and the anti-state carrier pool is used to tunnel anti-state carriers into the recombination region, so that the electron-hole recombination emits single light son. The above modes can use an external drive circuit to control the switching speed by controlling the gate, so the single-photon light-emitting element of the present invention can be regarded as a single-exciton transistor, and because the quantum dots in the SET and SHT are externally tunneled (insulating ) layer, also has the opportunity to operate at room temperature. In addition, if the single-photon light-emitting element of the present invention is arranged in a structure with an optical resonant cavity, the emission efficiency of the quantum dots can be significantly improved.

Although the present invention has been disclosed above by the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the scope of the appended patent application.

10: Single-photon light-emitting element

100: Stacked Structure

102a: source

102b: Drain

104: External drive circuit

106: Single Electron Quantum Dots

108: The first tunneling layer

110: Single Electron Gate Structure

112: Single-hole quantum dots

114: Second Tunneling Layer

116: Single-hole gate structure

Claims (24)

A single-photon light-emitting element, comprising: stack structure; a source electrode and a drain electrode, respectively disposed on opposite sides of the stacked structure; and an external drive circuit configured to output a drive signal, wherein The stacked structure includes: Single electron quantum dots; a first tunneling layer, completely covering the single-electron quantum dots; a single-electron gate structure, which completely surrounds the single-electron quantum dot and is isolated from the single-electron quantum dot through the first tunneling layer; a single hole quantum dot adjacent to the single electron quantum dot; a second tunneling layer completely covering the single-hole quantum dots; and a single-hole gate structure, which completely surrounds the single-hole quantum dot and is isolated from the single-hole quantum dot through the second tunneling layer, and According to the driving signal, the single-electron tunneling of the single-electron quantum dot is controlled to be injected into the single-hole quantum dot, so that the electron-hole recombination in the single-hole quantum dot emits a single photon; or the single-hole quantum dot is controlled The single hole of the hole quantum dot is injected into the single electron quantum dot, so that the electron hole recombines in the single electron quantum dot to emit a single photon. The single-photon light-emitting element according to claim 1, wherein the single-electron quantum dots are N-type direct energy gap semiconductor quantum dots or metal quantum dots. The single-photon light-emitting element according to claim 1, wherein the single-hole quantum dots are P-type direct energy gap semiconductor quantum dots. The single-photon light-emitting element according to claim 1, wherein the single-electron quantum dot and the single-hole quantum dot are made of the same material or different materials. The single-photon light-emitting element according to claim 1, wherein the number of single-electron quantum dots is plural, the number of single-hole quantum dots is single, and the plurality of single-electron quantum dots are the same as the Single single-hole quantum dots are stacked on top of each other. The single-photon light-emitting element according to claim 1, wherein the number of the single-electron quantum dots is single, the number of the single-hole quantum dots is multiple, and the single single-electron quantum dot is the same as the Multiple single-hole quantum dots are stacked on top of each other. The single-photon light-emitting element according to claim 1, wherein the number of the single-electron quantum dots is multiple, the number of the single-hole quantum dots is multiple, and the multiple single-electron quantum dots are the same as the single-electron quantum dots. A plurality of single-hole quantum dots are horizontally adjacent to each other. The single-photon light-emitting element according to claim 1, wherein the number of the single-electron quantum dots is multiple, the number of the single-hole quantum dots is multiple, and the multiple single-electron quantum dots are the same as the single-electron quantum dots. Multiple single-hole quantum dots are arranged in pairs up and down. A single-photon light-emitting element, comprising: stack structure; a source electrode and a drain electrode, respectively disposed on opposite sides of the stacked structure; and an external drive circuit configured to output a drive signal, wherein The stacked structure includes: Single electron quantum dots; a first tunneling layer, completely covering the single-electron quantum dots; a single-electron gate structure, which completely surrounds the single-electron quantum dot and is isolated from the single-electron quantum dot through the first tunneling layer; Single hole quantum dots; The second tunneling layer completely covers the single-hole quantum dot; a single-hole gate structure completely surrounding the single-hole quantum dot and isolated from the single-hole quantum dot through the second tunneling layer; and an undoped (undoped) direct energy gap semiconductor layer between the single-electron quantum dots and the single-hole quantum dots and passing through the first tunneling layer and the second tunneling layer, are isolated from the single-electron quantum dot and the single-hole quantum dot, respectively, and According to the driving signal, the single electron of the single electron quantum dot and the single hole of the single hole quantum dot are controlled to be tunneled into the undoped direct energy gap semiconductor layer, so that the electron hole is injected into the undoped direct energy gap semiconductor layer. The undoped direct-gap semiconductor layer recombines to emit single photons. The single-photon light-emitting element according to claim 9, wherein the single-electron quantum dots are N-type direct energy gap semiconductor quantum dots or metal quantum dots. The single-photon light-emitting element according to claim 9, wherein the single-hole quantum dots are P-type direct energy gap semiconductor quantum dots. The single-photon light-emitting element according to claim 9, wherein the single-electron quantum dots and the single-hole quantum dots are made of the same material or different materials. The single-photon light-emitting element as claimed in claim 9, further comprising: a control gate structure completely surrounding the undoped direct gap semiconductor layer; and An insulating layer is located between the control gate structure and the undoped direct energy gap semiconductor layer. The single-photon light-emitting element according to claim 9, wherein the undoped direct energy gap semiconductor layer is a quantum dot layer or a quantum well layer. A single-photon light-emitting element, comprising: stack structure; a source electrode and a drain electrode, respectively disposed on opposite sides of the stacked structure; and an external drive circuit configured to output a drive signal, wherein The stacked structure includes: A quantum dot, the quantum dot is one of a single electron quantum dot and a single hole quantum dot; a tunneling layer, completely covering the quantum dots; a control gate structure that completely surrounds the quantum dots and is isolated from the quantum dots through the tunneling layer; and an anti-state doped region carrier pool adjacent to the quantum dots and in an opposite conductive state to the quantum dots and isolated from the quantum dots by the tunneling layer, and According to the driving signal, the single electron or single hole of the quantum dot is controlled to be injected into the anti-state carrier pool through tunneling, so that the electron-hole recombination in the anti-state carrier pool emits a single photon. The single-photon light-emitting element according to claim 15, wherein the single-electron quantum dots are N-type direct energy gap semiconductor quantum dots or metal quantum dots. The single-photon light-emitting element according to claim 15, wherein the single-hole quantum dots are P-type direct energy gap semiconductor quantum dots. The single-photon light-emitting element of claim 15, wherein the quantum dots are the single-electron quantum dots, and the anti-state carrier pool is a P-type carrier pool. The single-photon light-emitting element of claim 15, wherein the quantum dot is the single-hole quantum dot, and the anti-state carrier pool is an N-type carrier pool. The single-photon light-emitting element according to claim 15, wherein the anti-state carrier pool is a one-dimensional or two-dimensional or three-dimensional semiconductor structure. The single-photon light-emitting element according to claim 20, wherein the one-dimensional semiconductor structure includes a nanowire, the two-dimensional semiconductor structure includes a quantum well, and the three-dimensional semiconductor structure includes a quantum well. Including the block (Bulk). A light-emitting device, comprising: a structure having an optical resonant cavity; and The single-photon light-emitting element according to any one of claims 1 to 21, which is arranged in the structure having an optical resonant cavity. The light-emitting device of claim 22, wherein the structure having an optical resonant cavity includes a micropillar structure, a photonic crystal structure or a microdisk structure. The light-emitting device of claim 22, further comprising a Bragg reflector (DBR) outer cavity surrounding the structure having the optical resonant cavity.

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