Quantum Dot Single Photon Emitter Technology 2026
Quantum Dot Single Photon Emitter Landscape 2026
Quantum dot single photon emitters are advancing from cryogenic laboratory demonstrations toward room-temperature, CMOS-compatible photonic integration. This dataset snapshot maps five material families, key assignees, and emerging directions from 2004–2026.
QD-SPE Technology: Material Platforms and Performance Benchmarks
Quantum dot single photon emitters (QD-SPEs) exploit discrete energy levels from three-dimensional quantum confinement to produce antibunched photon emission, characterized by a second-order correlation function g²(0) < 0.5. State-of-the-art values in retrieved records approach g²(0) < 0.02, with one InGaAs/GaAs result achieving g²(0) = 0.027 ± 0.005 at the telecom O-band.
Five principal material families are covered in this dataset: III-V self-assembled epitaxial QDs (InAs/GaAs, InAs/InP, InGaAs/GaAs), III-nitride QDs (GaN, InGaN/GaN), colloidal QDs (CdSe/CdS, CdSe/ZnSe, CsPbX₃ perovskites, PbS), group-IV and 2D material emitters, and hybrid photonic integration platforms marrying QD emitters to silicon, silicon carbide, and silicon nitride photonic circuits.
The field spans three identifiable phases in retrieved records: a foundational phase (2004–2012) confirming antibunching from InP and CdSe QDs; a development phase (2013–2019) focused on deterministic fabrication and photonic integration; and a maturation phase (2020–2026) dominated by reproducibility benchmarking, room-temperature perovskite QDs, and heterogeneous silicon integration.
In this dataset, the US dominates active patent filings among identified assignees, with the Indian Institute of Science emerging as the most recently active filer (2025, 2026). Najing Technology Corporation Limited holds two active US patents, and US Government / NIST holds two active patents covering waveguide-integrated single quantum emitter architectures in retrieved records.
Innovation Phases and Assignee Activity in Retrieved Records
Analysis of publication and filing dates across retrieved results reveals three distinct innovation phases from 2004 to 2026. The most recent cluster (2020–2026) shows intensifying activity around room-temperature operation, CMOS integration, and colloidal QD architectures.
Active Patent Assignees by Filing Count (Dataset Snapshot)
In this dataset, the Indian Institute of Science and US Government / NIST each hold two active patent filings, while Najing Technology Corporation Limited holds two active US patents — making these the most active named assignees in retrieved records.
↗ Click bars to exploreQD-SPE Publications and Filings by Innovation Phase (Dataset Snapshot)
In this dataset, the Maturation Phase (2020–2026) contains the largest concentration of retrieved results, with at least 15 records, compared to approximately 10 in the Development Phase (2013–2019) and around 6 in the Foundational Phase (2004–2012).
↗ Click bars to exploreKey Application Areas for QD Single Photon Emitters
Retrieved records identify four principal application domains for QD-SPEs: quantum key distribution, photonic quantum computing, quantum radiometry, and free-space optical communication. Each domain places distinct demands on emission wavelength, purity, and operating temperature.
Quantum Key Distribution Systems
A 2012 study demonstrated free-space QKD over 40 cm using electrically driven InAs QD emitters, achieving sifted key rates of 27.2 kbits/s at a QBER of 3.9%. A 2018 result demonstrated entangled photon generation from InP QD devices at 87 ± 4% fidelity, targeting fiber-based quantum network infrastructure at the standard telecom window around 1,550 nm. A 2021 InGaN/GaN QD result achieved g²(0) = 0.043, described as sufficient for use in quantum key distribution systems.
Quantum CommunicationPhotonic Quantum Processors
A 2022 study demonstrated large-number simultaneously controllable QD emitters in nanophotonic circuits as a prerequisite for chip-scale quantum processors. Najing Technology Corporation Limited's active US patents (2020, 2021) explicitly claim protection for "a quantum computing system comprising a single photon source device." A 2021 review covers photon-photon nonlinear quantum gates enabled by QD deterministic photon-emitter interfaces for scalable photonic quantum technology.
Quantum ComputingQuantum Radiometry and Detector Calibration
A 2022 review documents European National Metrology Institutes (NMIs) actively investigating QD-based single photon sources for calibration of single photon detectors in terms of photon flux and single-photon purity. QD-SPEs are positioned as primary quantum radiometric standards, requiring high purity (g²(0) well below 0.5) and traceable emission rates. This application domain places particular emphasis on source reproducibility, as benchmarked by a 2020 study of 15 simultaneously fabricated sources.
Quantum SensingFree-Space Optical Communication Links
A 2021 study reports CdSe/ZnSe QD emitters in semiconductor tapered nanocolumns achieving count rates exceeding 5 MHz with g²(0) = 0.25 at 220 K, described as promising for secure free-space optical communication lines. The visible spectral range emission from these bright single-photon emitters is engineered via multimode tapered nanoantenna structures. This approach operates at elevated temperatures relative to cryogenic III-V systems, reducing infrastructure requirements for deployment.
Free-Space OpticalKey Patent Assignees in QD Single Photon Emitters (Retrieved Records)
In this dataset, seven named assignees hold patent filings across the QD-SPE landscape. The Indian Institute of Science (IN) and US Government / NIST (US) each account for two active filings in retrieved records, with the most recent filings dated 2025 and 2026 from the Indian Institute of Science.
Active Patent Filings per Assignee — QD-SPE (Dataset Snapshot)
↗ Click bars to exploreIndian Institute of Science
The Indian Institute of Science holds two active patent filings in this dataset, with filing dates in 2025 and 2026 — the most recent filings in the entire retrieved dataset. Both patents cover colloidal quantum dot single photon emitters using a multi-layered QD structure with an inverted band gap (wider gap core, narrower bandgap shell) engineered to non-radiatively recombine multi-excitons and emit a single photon. The 2026 filing (IN, active) represents the leading edge of colloidal QD SPE IP activity in this dataset.
India — INUS Government / NIST
US Government / NIST holds two active US patents in this dataset, filed in 2020 and 2022, covering waveguide-integrated single quantum emitter sources. The 2022 patent covers a waveguide-integrated single quantum emitter source using evanescent coupling between single-mode excitation and multimode intermediate waveguides. A separate 2017 US Government patent (active) covers a single photon source based on a quantum dot molecule in an optical cavity. These filings represent core waveguide-integration IP that commercial entrants targeting on-chip QD-SPS integration in the US market must address.
United States — USFive Emerging Directions in QD Single Photon Emitter R&D (2022–2026)
The most recent filings and publications in this dataset (2022–2026) point to five converging directions: room-temperature perovskite QDs with cavity enhancement, inverted-bandgap colloidal QD architectures, CMOS-compatible hybrid integration, position-controlled telecom emitters at elevated temperatures, and machine-learning-optimized multi-emitter systems.
Room-Temperature Perovskite QDs Approaching Competitive Purity
A 2022 systematic study of approximately 170 CsPbX₃ QDs demonstrated 98% single-photon purity (g²(0) = 2%) from a 6.6 nm CsPbI₃ QD at room temperature using quantum confinement to suppress biexciton yield. A 2023 result placed a CsPbI₃ QD in a tunable open-access microcavity, producing single-mode photons at 5 MHz rate with 94% purity and approximately 1 nm linewidth at room temperature. These results suggest perovskite QD systems are approaching competitive purity relative to cryogenic III-V systems for applications where operating temperature is a primary constraint.
Hybrid CMOS Integration: SiC and SOI Platforms
A 2022 study demonstrated InGaAs QD single-photon sources hybrid-integrated with 4H-SiC photonic chips via ion slicing, with a bilayer vertical coupler enabling efficient single-photon routing and on-chip beamsplitting. A separate 2022 result showed InAs/InP QDs heterogeneously integrated with Si substrates achieving approximately 10% photon extraction efficiency. Transfer printing of InAs/GaAs QD sources onto CMOS silicon photonic waveguides was demonstrated in 2019, establishing a scalable foundry-compatible pathway for III-V QD integration.
Epitaxial III-V QDs vs. Colloidal / Perovskite QDs: Key Dimensions
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| Dimension | Epitaxial III-V QDs (InAs/GaAs, InAs/InP) | Colloidal / Perovskite QDs (CdSe, CsPbX₃) |
|---|---|---|
| Operating Temperature | Typically 4–40 K (cryogenic); elevated-temperature work to 300 K emerging (2023) | Room temperature demonstrated; 220 K for CdSe/ZnSe; 300 K for CsPbI₃ |
| Best g²(0) in Retrieved Records | 0.021 (InAsP in InP nanowire, 2023); 0.027 ± 0.005 (InGaAs/GaAs, 2020) | 0.02 (g²(0) = 2%) from 6.6 nm CsPbI₃ QD at room temperature (2022) |
| Photon Purity Benchmark | Average 95.4% ± 1.5% across 15 sources (2020 reproducibility study) | 98% single-photon purity from CsPbI₃ QD at room temperature (2022) |
| Telecom Band Compatibility | InAs/InP natively at C-band (1,550 nm) and O-band (1,310 nm); photon rates exceeding 0.5 GHz | Primarily visible range; telecom extension requires frequency conversion |
| Photonic Integration Pathway | Transfer printing to CMOS silicon photonics; ion slicing to SiC; heterogeneous Si integration | Solution-processed; nanophotonic integration of colloidal QDs demonstrated (2022) |
| Fabrication Infrastructure | MBE / MOCVD epitaxy; wafer-scale on 3-inch substrates demonstrated (2021) | Solution synthesis; no UHV deposition required; scalable colloidal chemistry |
| Key Patent Assignees in Dataset | US Government / NIST (×2 active), Najing Technology Corp. (×2 active), TU Berlin (lapsed) | Indian Institute of Science (×2 active, 2025–2026) |
Frequently Asked Questions: Quantum Dot Single Photon Emitters
A quantum dot single photon emitter is a nanoscale semiconductor structure that exploits three-dimensional quantum confinement to produce antibunched photon emission — one photon at a time on demand. Purity is characterized by the second-order correlation function g²(0); values below 0.5 confirm single-photon emission, with state-of-the-art results in retrieved records approaching g²(0) < 0.02.
Five principal material families appear in retrieved records: (1) III-V self-assembled epitaxial QDs including InAs/GaAs, InAs/InP, and InGaAs/GaAs; (2) III-nitride QDs such as GaN and InGaN/GaN; (3) colloidal QDs including CdSe/CdS, CdSe/ZnSe, CsPbX₃ perovskites, and PbS; (4) group-IV and 2D material emitters used in comparative context; and (5) hybrid photonic integration platforms on silicon, silicon carbide, and silicon nitride.
Yes, based on retrieved records. A 2022 study demonstrated 98% single-photon purity (g²(0) = 2%) from a 6.6 nm CsPbI₃ perovskite QD at room temperature. A 2023 result placed a CsPbI₃ QD in a tunable open-access microcavity, achieving 94% purity and approximately 1 nm linewidth at room temperature with a 5 MHz emission rate. CdSe/ZnSe QDs in tapered nanocolumns showed g²(0) = 0.25 at 220 K.
Seven named assignees are identified in retrieved records: Indian Institute of Science (IN, 2 active filings, 2025–2026), US Government / NIST (US, 2 active filings, 2020–2022), Najing Technology Corporation Limited (US, 2 active filings, 2020–2021), US Government (US, 1 active filing, 2017), Creeled Inc. (US, 1 active filing, 2017), Sharp Kabushiki Kaisha (US, 1 inactive filing, 2021), and Technische Universitaet Berlin (US, 1 lapsed filing, 2010).
Retrieved records identify four principal application domains: quantum key distribution (QKD), where a 2012 study achieved 27.2 kbits/s sifted key rate with a 3.9% QBER; photonic quantum computing, with Najing Technology patents explicitly claiming quantum computing system applications; quantum radiometry, where European NMIs use QD-SPEs for single photon detector calibration; and free-space optical communication, where CdSe/ZnSe QDs exceeded 5 MHz count rates at 220 K.
Based on the most recent retrieved records (2022–2026), five emerging directions are identified: room-temperature perovskite QD emitters with cavity enhancement; inverted-bandgap colloidal QD architectures (Indian Institute of Science, 2025–2026 patents); hybrid CMOS-compatible integration on SiC and SOI platforms; position-controlled telecom QD emitters operating up to 300 K with g²(0) = 0.021 at 1.31 µm; and machine-learning-optimized five-dipole-coupled-emitter systems for perfect indistinguishability at elevated temperatures.
Data and insights on this page are based on a limited patent and literature dataset and are for reference only. Figures may not represent the complete technology landscape.