Study on Diamond NV Centers Excited by Green Light Emission from OLEDs

At a Glance

Metadata	Details
Publication Date	2025-08-22
Journal	Photonics
Authors	Yangyang Guo, Xin Li, Fuwen Shi, Wenjun Wang, Bo Li
Institutions	Liaocheng University, East China Normal University
Analysis	Full AI Review Included

Technical Documentation & Analysis: Diamond NV Centers Excited by Green Light Emission from OLEDs

Executive Summary

This research successfully demonstrates a highly efficient, miniaturized platform for exciting diamond Nitrogen-Vacancy (NV) centers using optimized Organic Light-Emitting Diodes (OLEDs), establishing a new pathway for quantum sensing applications.

Core Achievement: Integration of diamond NV centers with planar OLED light sources, enabling system miniaturization compared to conventional LED/laser systems.
Performance Enhancement: Interfacial engineering (using a GO/PEDOT:PSS hybrid anode) resulted in a 3.7-fold increase in NV center fluorescence peak intensity compared to standard ITO anodes.
Quantum Sensing Metric: The optimized anode achieved a twofold enhancement in the Optically Detected Magnetic Resonance (ODMR) Signal-to-Noise Ratio (SNR), reaching 41 SNR.
Efficiency Gains: The optimized device operated at a significantly lower voltage (14 V vs. 19.5 V for ITO) and demonstrated a 22% reduction in power consumption (88 mW vs. 114 mW).
Material Requirement: The experiment relied on Type Ib Single Crystal Diamond (SCD) substrates with controlled nitrogen concentration (~100 ppm) to facilitate high-density NV center creation via electron irradiation and annealing.
Miniaturization: A compact quantum sensor prototype (22 mm x 14 mm x 7 mm) was successfully implemented, leveraging the surface-emitting nature of OLEDs.

Technical Specifications

Parameter	Value	Unit	Context
Diamond Type	Type Ib SCD	N/A	Substrate material for NV centers
Diamond Orientation	(110)	N/A	Crystal plane orientation
Diamond Dimensions	3 x 3 x 1	mm	Sample size used in the experiment
Nitrogen Concentration	~100	ppm	Initial concentration in the diamond substrate
NV Creation Dose	1 x 10¹⁸	e^-/cm²	Electron beam irradiation dose
Annealing Temperature	800	°C	Post-irradiation thermal treatment
Fluorescence Enhancement	3.7	fold	Optimized hybrid anode vs. ITO anode (Max Intensity)
ODMR SNR (Optimized)	41	N/A	GO/PEDOT:PSS (40%) hybrid anode
ODMR Contrast Ratio (CR)	3.0	%	GO/PEDOT:PSS (40%) hybrid anode
Operating Voltage (Optimized)	14	V	Required for equivalent NV center intensity
Power Consumption Reduction	22	%	Optimized hybrid anode vs. ITO reference
Anode Conductivity (Max)	4032	S/cm	GO/PEDOT:PSS (40%) composite film
Anode Work Function (Max)	5.014	eV	GO/PEDOT:PSS (40%) composite film

Key Methodologies

The core innovation lies in the interfacial engineering of the OLED anode and the preparation of high-quality NV-doped diamond.

GO/PEDOT:PSS Hybrid Anode Preparation: Graphene Oxide (GO) was prepared (0.5 mg/mL) and blended with PEDOT:PSS at varying ratios (10%, 40%, 100%). The solution was spin-coated onto quartz/ITO substrates (3000 rpm for 30 s) and annealed at 120 °C for 20 min.
Acid-Modified Interface Engineering: The hybrid films underwent acid treatment (1 M HCl at 160 °C for 30 min, or 1 M H₂SO₄ at 160 °C for 1 h) followed by deionized water rinsing. This process promoted dissociation of PEDOT⁺ from PSS^- chains, significantly enhancing film conductivity and work function.
OLED Device Fabrication: Organic layers (MoO₃, NPB, Alq₃, BPhen, LiF) and the Al cathode were sequentially evaporated under high vacuum (< 5 x 10^-4 Pa) onto the prepared anodes.
Diamond Substrate Preparation: Type Ib diamond substrates (3 mm x 3 mm x 1 mm, (110) plane, ~100 ppm N) were subjected to electron beam irradiation (1 x 10¹⁸ e^-/cm²).
NV Center Formation: Post-irradiation annealing was performed at 800 °C for 1 h under a high-purity nitrogen protective atmosphere to mobilize vacancies and form high-density NV centers.
Sensor Integration: The NV-doped diamond sample was fixed onto the light-emitting surface of the OLED using thermal adhesive, integrated with a microstrip antenna for ODMR measurements.

6CCVD Solutions & Capabilities

This research validates the critical role of high-quality, customized Single Crystal Diamond (SCD) in advancing miniaturized quantum sensors. 6CCVD is uniquely positioned to supply the necessary materials and engineering services to replicate, scale, and optimize this technology.

Applicable Materials

To replicate and extend the performance achieved in this study, researchers require high-ppurity diamond with precise nitrogen control.

Material Specification	6CCVD Offering	Relevance to Research
SCD Substrates (Type Ib Equivalent)	Controlled Nitrogen SCD	Provides the necessary nitrogen precursors (~100 ppm) for high-density NV center formation via irradiation/annealing.
Crystal Orientation	Custom (110) or (100) SCD	The paper used (110). 6CCVD offers custom orientations, allowing researchers to optimize NV alignment and spin coherence properties.
High Purity SCD	Optical Grade SCD	Essential for minimizing background fluorescence and maximizing the signal-to-noise ratio (SNR) of the NV center emission (637 nm zero-phonon line).

Customization Potential

The miniaturized sensor design (22 mm x 14 mm x 7 mm) and the use of a microstrip antenna highlight the need for precise material handling and integration capabilities, which are core strengths of 6CCVD.

Custom Dimensions and Scaling: While the paper used small 3 mm x 3 mm samples, 6CCVD can supply SCD plates up to 125 mm (PCD) and custom SCD wafers, enabling the scaling of this OLED-NV platform for commercial production or larger array sensors.
Precision Polishing: Achieving optimal optical coupling between the OLED and the diamond requires extremely low surface roughness. 6CCVD offers SCD polishing down to Ra < 1 nm, ensuring minimal scattering losses and maximizing excitation efficiency.
Integrated Metalization: The device requires a microstrip antenna for microwave delivery (ODMR). 6CCVD offers in-house custom metalization services (Au, Pt, Ti, Pd, W, Cu) applied directly to the diamond surface, facilitating integrated device fabrication and reducing assembly complexity.
Thickness Control: 6CCVD provides precise thickness control for SCD (0.1 µm to 500 µm) and substrates (up to 10 mm), allowing engineers to optimize the diamond volume for specific NV density requirements and thermal management within compact devices.

Engineering Support

6CCVD’s in-house PhD team specializes in MPCVD growth parameters tailored for quantum applications.

Material Selection Consultation: We assist researchers in selecting the optimal initial nitrogen concentration and crystal orientation to maximize NV yield and coherence time following post-processing (electron irradiation and annealing).
Quantum Sensing Projects: Our team provides expert guidance on material specifications for similar OLED-Excited Quantum Sensing projects, ensuring the supplied diamond meets the stringent requirements for high SNR and high contrast ratio ODMR.

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

View Original Abstract

This study demonstrates the feasibility of exciting NV centers using ITO-anode OLED devices, followed by the fabrication of GO/PEDOT:PSS hybrid anodes via spin-coating. Through interfacial modification, the OLED devices exhibit significantly enhanced luminescence intensity, leading to improved NV center excitation efficiency. Experimental results show that the optimized GO/PEDOT:PSS (40%) hybrid anode device achieves a lower turn-on voltage, with the NV center fluorescence peak intensity reaching 3.7 times that of the ITO-anode device, confirming the enhanced excitation effect through interfacial engineering of the light source. By integrating NV centers with OLED technology, this work establishes a new approach for efficient excitation. This integration approach provides a new pathway for applications such as quantum sensing.

Tech Support

Original Source

DOI: https://doi.org/10.3390/photonics12090833

References

2023 - Broadband microwave detection using electron spins in a hybrid diamond-magnet sensor chip [Crossref]
2016 - Quantitative nanoscale vortex imaging using a cryogenic quantum magnetometer [Crossref]
2015 - Broadband magnetometry and temperature sensing with a light-trapping diamond waveguide [Crossref]
2015 - High-sensitivity temperature sensing using an implanted single nitrogen-vacancy center array in diamond [Crossref]
2013 - High-precision nanoscale temperature sensing using single defects in diamond [Crossref]
2021 - Demonstration of diamond nuclear spin gyroscope [Crossref]
2018 - Quantum measurement of a rapidly rotating spin qubit in diamond [Crossref]
2011 - Real time magnetic field sensing and imaging using a single spin in diamond [Crossref]
2018 - T2-limited sensing of static magnetic fields via fast rotation of quantum spins [Crossref]
2022 - Picotesla magnetometry of microwave fields with diamond sensors [Crossref]