Ultrabright single-photon source on diamond with electrical pumping at room and high temperatures

At a Glance

Metadata	Details
Publication Date	2016-07-06
Journal	New Journal of Physics
Authors	D. Yu. Fedyanin, M. Agio, D. Yu. Fedyanin, M. Agio
Institutions	University of Siegen, National Research Council
Citations	57
Analysis	Full AI Review Included

Technical Documentation & Analysis: Ultrabright Single-Photon Source on Diamond

Executive Summary

This research establishes a critical theoretical foundation for developing high-performance, electrically driven single-photon sources (SPS) based on diamond color centers. The findings directly validate the use of MPCVD diamond for next-generation quantum communication and computation operating at unprecedented temperatures.

Core Achievement: Development of a comprehensive theoretical model describing electroluminescence from diamond color centers (NV, SiV) embedded in a p-n junction diode structure.
High-Temperature Performance: Demonstrates superior emission properties at elevated temperatures, contrasting sharply with conventional semiconductor devices.
Record Emission Rate: Predicts a maximum photon emission rate exceeding 10⁸ counts s^-1 (100 Mcounts s^-1) at 500 K, significantly higher than previously reported rates (10⁴ counts s^-1).
Scalability & Bandwidth: Identifies that reducing the n-type compensation ratio (from 10% to 0.4%) is the key technological pathway to achieve gigahertz bandwidth SPS operation.
Material Requirement: Requires high-quality, precisely doped (Boron and Phosphorus) CVD diamond layers for robust p-n junction fabrication and controlled color center integration.
6CCVD Value: 6CCVD provides the necessary high-purity Single Crystal Diamond (SCD) and heavily Boron-Doped Diamond (BDD) substrates and epitaxial layers required to realize these high-performance quantum devices.

Technical Specifications

The following hard data points were extracted from the simulation parameters and predicted performance metrics of the diamond single-photon emitting diode:

Parameter	Value	Unit	Context
Max Photon Emission Rate (500 K)	>10⁸ (100)	counts s^-1 (Mcounts s^-1)	High-temperature operation
Max Photon Emission Rate (300 K)	100	kcounts s^-1	Standard room temperature operation
Required Bandwidth Target	Gigahertz	Range	Achievable with improved doping
P-type Acceptor Concentration (N_A)	5 × 10¹⁸	cm^-3	Boron-doped layer
N-type Donor Concentration (N_D)	3 × 10¹⁸	cm^-3	Phosphorus-doped layer
Standard N-type Compensation Ratio ($\eta_n$)	10	%	Limits room temperature performance
Optimized N-type Compensation Ratio ($\eta_n$)	0.4	%	Required for gigahertz operation
Diode Layer Thickness (p-type/n-type)	300	nm	Nanoscale junction structure
Electron Mobility ($\mu_n$)	220	cm²V^-1s^-1	Simulated carrier transport
Hole Mobility ($\mu_p$)	290	cm²V^-1s^-1	Simulated carrier transport
NV⁰ Quantum Efficiency ($\Phi$)	30	%	Used for emission rate calculation [47]
SiV^- Quantum Efficiency ($\Phi$)	5	%	Used for emission rate calculation [21]

Key Methodologies

The study utilized a comprehensive computational approach to model the single-photon emitting diamond diode structure and predict its performance under electrical injection.

Theoretical Model Development: Established a multi-stage process model for electroluminescence, accounting for electron/hole trapping, carrier thermal escape, and structural transformations of the color center (e.g., NV^- to NV⁰).
Device Structure: Simulated a p-n junction diamond diode with 300 nm thick p-type (Boron-doped) and n-type (Phosphorus-doped) layers, embedding the color center in the vicinity of the junction (optimal position 3-8 nm).
Carrier Dynamics Simulation: Employed a self-consistent steady-state model integrating the Poisson equation, drift-diffusion current equations, and electron/hole continuity equations to accurately describe carrier behavior in the doped diamond layers.
Recombination Rate Calculation: Derived the photon emission rate ($R_{ph}$) based on the Shockley-Read-Hall recombination model, simplified for deep-level color centers, showing $R_{ph}$ is limited by the inverse sum of electron capture, hole capture, and excited-state transition rates.
Thermal Analysis: Investigated the input-output characteristics across a wide temperature range (300 K to 500 K), demonstrating that heating the device significantly increases the density of free electrons in the n-type layer, thereby boosting the emission rate.

6CCVD Solutions & Capabilities

The successful realization of an ultrabright, electrically pumped diamond single-photon source hinges on high-quality MPCVD diamond materials with precise doping control and advanced integration capabilities—all core competencies of 6CCVD.

Applicable Materials for Replication and Extension

To replicate or extend this research, engineers require highly controlled, high-purity diamond material for both the active layers and the substrate.

Research Requirement	6CCVD Material Solution	Technical Specification Match
P-type Layer (N_A = 5×10¹⁸ cm^-3)	Heavy Boron-Doped Diamond (BDD)	Provides highly conductive p-type layers necessary for efficient hole injection. We offer BDD films with precise doping control.
High-Purity Active Region	Optical Grade Single Crystal Diamond (SCD)	Essential for controlled creation of high-coherence NV and SiV centers via implantation or in-situ growth. Polishing available to Ra < 1 nm.
Scalable Device Fabrication	Polycrystalline Diamond (PCD) Substrates	For large-area arrays, 6CCVD offers PCD wafers up to 125 mm in diameter, enabling mass production of integrated quantum devices.
N-type Layer Template	High-Purity SCD Substrates	Provides the ideal template for subsequent n-type (Phosphorus) doping and epitaxial growth, minimizing background impurities that cause compensation.

Customization Potential for Advanced Integration

The paper notes that emission properties can be further improved using optical antennas or cavities [49-51]. 6CCVD offers the necessary fabrication and integration services to support these advanced designs.

Precise Thickness Control: The simulated p-n junction layers are 300 nm thick. 6CCVD specializes in epitaxial growth with thickness control ranging from 0.1 µm to 500 µm for both SCD and PCD, ensuring optimal junction formation.
Custom Metalization for Ohmic Contacts: The diode requires reliable ohmic contacts for electrical injection. 6CCVD offers in-house metalization services, including Ti, Pt, Au, Pd, W, and Cu, allowing researchers to optimize contact resistance and thermal management.
Nanoscale Fabrication: We provide advanced processing services, including precision laser cutting and etching, crucial for defining the nanoscale diode geometry and integrating photonic structures (e.g., waveguides or micro-pillars) onto the diamond surface.

Engineering Support

The primary technological challenge identified in this research is the high compensation ratio ($\eta_n$) in n-type diamond, which limits the free electron density and, consequently, the photon emission rate at room temperature.

Doping Optimization: 6CCVD’s in-house PhD team specializes in CVD diamond growth and defect engineering. We offer consultation and custom growth recipes to assist clients in minimizing compensation effects and achieving the low $\eta_n$ (0.4%) required for gigahertz bandwidth single-photon sources.
Thermal Management: Given the predicted superior performance at 500 K (227 °C), 6CCVD can assist in selecting diamond substrates (up to 10 mm thick) and metalization schemes optimized for high-temperature operation and efficient heat dissipation.
Global Supply Chain: We offer reliable global shipping (DDU default, DDP available) to ensure rapid delivery of custom diamond materials worldwide, supporting time-sensitive quantum research projects.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

The recently demonstrated electroluminescence of color centers in diamond\nmakes them one of the best candidates for room temperature single-photon\nsources. However, the reported emission rates are far off what can be achieved\nby state-of-the-art electrically driven epitaxial quantum dots. Since the\nelectroluminescence mechanism has not yet been elucidated, it is not clear to\nwhat extent the emission rate can be increased. Here we develop a theoretical\nframework to study single-photon emission from color centers in diamond under\nelectrical pumping. The proposed model comprises electron and hole trapping and\nreleasing, transitions between the ground and excited states of the color\ncenter as well as structural transformations of the center due to carrier\ntrapping. It provides the possibility to predict both the photon emission rate\nand the wavelength of emitted photons. Self-consistent numerical simulations of\nthe single-photon emitting diode based on the proposed model show that the\nphoton emission rate can be as high as 100 kcounts s$^{-1}$ at standard\nconditions. In contrast to most optoelectronic devices, the emission rate\nsteadily increases with the device temperature achieving of more than 100\nMcount s$^{-1}$ at 500 K, which is highly advantageous for practical\napplications. These results demonstrate the potential of color centers in\ndiamond as electrically driven non-classical light emitters and provide a\nfoundation for the design and development of single-photon sources for optical\nquantum computation and quantum communication networks operating at room and\nhigher temperatures.\n

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Original Source

DOI: https://doi.org/10.1088/1367-2630/18/7/073012