Efficient heat dissipation perovskite lasers using a high-thermal-conductivity diamond substrate

At a Glance

Metadata	Details
Publication Date	2023-02-28
Journal	Science China Materials
Authors	Guohui Li, Zhen Hou, Yanfu Wei, Ruofan Zhao, Ting Ji
Institutions	Taiyuan University of Technology, Lund University
Citations	17
Analysis	Full AI Review Included

Technical Documentation & Analysis: High-Thermal-Conductivity Diamond for Perovskite Lasers

6CCVD Material Science Analysis of “Efficient heat dissipation perovskite lasers using a high-thermal-conductivity diamond substrate”

Executive Summary

This research successfully validates the use of high-thermal-conductivity diamond substrates as a critical enabling technology for stable, high-performance perovskite lasers, directly addressing the heat management bottleneck for future electrically driven devices.

Thermal Management Validation: The incorporation of a diamond substrate (thermal conductivity, k = 2400 W m⁻¹ K⁻¹) resulted in highly efficient heat dissipation during optical pumping.
Ultra-Low Sensitivity: The demonstrated laser achieved a pump-density-dependent temperature sensitivity of ~0.56 ± 0.01 K cm² µJ⁻¹, which is one to two orders of magnitude lower than previously reported glass-based perovskite nanowire lasers.
High Quality Factor: The optimized structure (MAPbI${3}$ nanoplatelet / 100 nm SiO${2}$ gap / Diamond) achieved a high Quality (Q) factor of ~1962, demonstrating effective vertical optical confinement via the low-refractive-index SiO$_{2}$ layer.
Material Superiority: Diamond’s thermal conductivity (2400 W m⁻¹ K⁻¹) significantly surpasses common alternatives used in laser substrates, including GaAs (50 W m⁻¹ K⁻¹), Sapphire (~25 W m⁻¹ K⁻¹), and Silicon Carbide (490 W m⁻¹ K⁻¹).
Path to Electrical Injection: The efficient thermal management demonstrated under pulsed excitation is directly applicable to continuous-wave (CW) and electrical injection scenarios, which require robust heat sinking to prevent thermal runaway and degradation.

Technical Specifications

The following hard data points were extracted from the research paper, highlighting the performance metrics achieved using the diamond substrate.

Parameter	Value	Unit	Context
Substrate Thermal Conductivity (Diamond)	2400	W m⁻¹ K⁻¹	Highest thermal conductivity material used.
Lasing Threshold (P$_{th}$)	52.19	µJ cm⁻²	Optimized structure (100 nm SiO$_{2}$/Diamond).
Quality Factor (Q)	~1962	N/A	Achieved with 100 nm SiO$_{2}$ gap layer.
Temperature Sensitivity (P-dependent)	0.56 ± 0.01	K cm² µJ⁻¹	Crucial metric for thermal stability.
Diamond Refractive Index (n$_{s}$)	~2.40	N/A	Used for vertical optical confinement analysis.
MAPbI${3}$ Refractive Index (n${p}$)	~2.56	N/A	High index material for WGM cavity.
SiO${2}$ Refractive Index (n${gap}$)	~1.454	N/A	Low index gap layer for Total Internal Reflection (TIR).
Optimal SiO$_{2}$ Gap Layer Thickness	100	nm	Optimized balance between confinement and heat transfer.
Diamond Substrate RMS Roughness (Pristine)	~0.7	nm	Essential for high thermal conduction efficiency.
MAPbI$_{3}$ Thermal Conductivity	1-3	W m⁻¹ K⁻¹	Low intrinsic thermal conductivity necessitating external heat sink.

Key Methodologies

The experimental success relied on precise material synthesis, transfer, and structural engineering to achieve optimal thermal and optical performance.

Perovskite Synthesis: MAPbI$_{3}$ nanoplatelets were synthesized on mica substrates using a Chemical Vapor Deposition (CVD) method.
Substrate Preparation: Square-shaped diamond substrates were prepared and coated with a low-refractive-index SiO$_{2}$ gap layer. Three thicknesses were tested: 50 nm, 100 nm, and 200 nm.
Transfer Printing: Nanoplatelets were transferred onto the SiO$_{2}$-coated diamond using thermal release tapes, ensuring the preservation of the nanoplatelet’s Whispering Gallery Mode (WGM) cavity morphology.
Surface Quality Control: Atomic Force Microscopy (AFM) confirmed the pristine diamond substrate achieved a Root Mean Square (RMS) roughness of ~0.7 nm, critical for efficient thermal contact.
Optical Confinement Analysis: Finite-element method simulations were used to analyze the electric field distribution, confirming that the SiO$_{2}$ gap layer was necessary to suppress leakage field into the diamond substrate and achieve strong vertical confinement.
Lasing Characterization: The devices were excited using a 343-nm femtosecond laser at room temperature (293 K). Performance was evaluated by monitoring the resonant wavelength shift (λ) as a function of pump density (P) to determine the thermal sensitivity.

6CCVD Solutions & Capabilities

The successful integration of high-quality diamond as a heat spreader is a direct application of 6CCVD’s core expertise in MPCVD diamond substrates. We offer the necessary materials and customization services to replicate, optimize, and scale this research for commercial applications, particularly in high-power photonics.

Applicable Materials

To replicate or extend this research, 6CCVD recommends the following materials:

Optical Grade Single Crystal Diamond (SCD): Required for the highest thermal conductivity (k > 2000 W m⁻¹ K⁻¹) and superior optical transparency in the UV-Vis spectrum, matching the substrate used in the study.
High-Purity Polycrystalline Diamond (PCD): For larger area devices (up to 125mm wafers) where cost-efficiency is paramount, 6CCVD PCD offers excellent thermal properties (k > 1000 W m⁻¹ K⁻¹) with controlled grain size.
Boron-Doped Diamond (BDD): For the critical transition to electrically driven lasers, 6CCVD provides BDD substrates that serve as highly conductive electrodes while maintaining excellent thermal sinking capabilities.

Customization Potential

The research utilized custom square diamond substrates and required ultra-smooth surfaces for optimal performance. 6CCVD specializes in meeting these precise engineering requirements:

Research Requirement	6CCVD Solution & Capability	Technical Advantage
Substrate Dimensions	Custom Plates/Wafers up to 125mm	We provide custom square or rectangular plates, or full wafers, up to 10mm thick, ensuring compatibility with existing fabrication tools.
Surface Quality	Precision Polishing (Ra < 1 nm)	Our SCD polishing capability guarantees surface roughness (Ra) below 1 nm, meeting the critical requirement for minimizing scattering losses and maximizing thermal contact efficiency (RMS ~0.7 nm achieved in the paper).
Heterostructure Integration	Custom Metalization Services	While the paper used SiO$_{2}$, 6CCVD offers in-house metalization (Au, Pt, Pd, Ti, W, Cu) for creating complex contact layers or adhesion layers necessary for subsequent dielectric deposition or electrical injection architectures.
Thickness Control	SCD/PCD Thickness Control (0.1 µm - 500 µm)	We provide substrates with precise thickness control, essential for managing thermal resistance and integration into microcavity designs.

Engineering Support

6CCVD’s in-house PhD team offers specialized consultation to accelerate development in high-power perovskite photonics:

Thermal Modeling: Assistance with material selection and thickness optimization to manage heat accumulation and minimize the pump-density-dependent temperature sensitivity in similar WGM Laser projects.
Optical Design: Support in selecting diamond grades and surface finishes necessary to maintain high Q factors and achieve effective Total Internal Reflection (TIR) in complex heterostructures.
Electrode Integration: Guidance on transitioning from optically pumped devices to stable, electrically injected lasers using optimized Boron-Doped Diamond (BDD) layers for low-resistance contacts and efficient heat removal.

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

View Original Abstract

Abstract Efficient heat dissipation that can minimize temperature increases in device is critical in realizing electrical injection lasers. High-thermal-conductivity diamonds are promising for overcoming heat dissipation limitations for perovskite lasers. In this study, we demonstrate a perovskite nanoplatelet laser on a diamond substrate that can efficiently dissipate heat generated during optical pumping. Tight optical confinement is also realized by introducing a thin SiO 2 gap layer between nanoplatelets and the diamond substrate. The demonstrated laser features a Q factor of ∼1962, a lasing threshold of 52.19 µJ cm −2 , and a low pump-density-dependent temperature sensitivity (∼0.56 ± 0.01 K cm 2 µJ −1 ) through the incorporation of the diamond substrate. We believe our study could inspire the development of electrically driven perovskite lasers.

Tech Support

Original Source

DOI: https://doi.org/10.1007/s40843-022-2355-6