Phase Change Material Research Articles

All‐Climate Thermal Management Performance of Power Batteries Based on Double‐Layer Flexible Phase Change Materials

AbstractThermal management systems for power batteries based on phase change materials (PCM) are limited by low heat transfer efficiency, leakage issues, and high rigidity, and most of them cannot meet the needs of all‐climate thermal management. A double‐layer flexible phase change material (FPCM) sleeve structure for all‐climate thermal management is proposed in this study for the first time. Innovations in both material and design have enhanced the adaptability of the thermal management system. The outer layer FPCM achieves high thermal conductivity (4.23 W m−1 K−1) and electrical conductivity (0.95 S m−1), the inner layer FPCM achieves insulation (22.76 MΩ) and flexibility, the thermal contact resistance (TCR) between the double‐layer sleeve structure and the battery are measured to be only 0.15 °C W−1, significantly improved thermal management performance. Experimental results show that at 30 °C ambient temperature, 5 C discharge, the system reduces the maximum temperature by 14.5 °C, from 61.4 to 46.9 °C, compared to natural convection. Additionally, during heating, the system achieves heating rates of 7.0, 8.3, and 8.7 °C min−1 at −20, −10, and 0 °C, respectively, extending battery discharge duration by 32.5%, 65.9%, and 33.6%.

A review on phase change material's applications in solar parabolic dish collectors

A review on phase change material's applications in solar parabolic dish collectors

Application of microencapsulated phase change materials for controlling exothermic reactions

Abstract Thermal runaway is a frequent source of process safety issues, and the uncontrolled release of chemical energy puts reactors at risk. The design of the exothermic reactor faces challenges due to the selective sensitivity of the product to high temperatures and the need to increase the lifetime of the catalyst, optimize the product distribution, and improve the thermodynamic properties. Phase change material (PCM) encapsulation is recommended to reduce leakage, phase separation, and volume change problems. This work introduces encapsulated PCMs to improve reactor temperature control and minimize thermal runaway in exothermic processes. The warning temperature value setting effectively inhibits fugitive exothermic reactions and enhances heat transfer. When a sufficient quantity of encapsulated PCMs is input, the response speed will automatically accelerate. Spontaneous acceleration of the reaction rate due to thermal runaway of the reaction may be completely avoided by adding a sufficient amount of encapsulated PCM. Microencapsulation is used to control volume changes and inhibit thermal reactions. Preventive strategies include cooling, depressurization, safety release, emergency resources, and reaction containment. Encapsulated PCMs improve mechanical and thermal properties, surface-to-volume ratio, heat transfer surface, thermal capacity, and efficiency.

Evaluating the energy and economic performance of hybrid photovoltaic thermal system integrated with multiwalled carbon nanotubes enhanced phase change material

Photovoltaic thermal (PVT) systems represent an advanced evolution of traditional photovoltaic (PV) modules designed to generate electrical and thermal energy simultaneously. However, achieving optimal and commercially viable performance from these systems remains challenging. To overcome this issue, in this research, multiwalled carbon nanotube (MWCNT) enhanced phase change materials (PCMs) integrated with PVT system to enhance electrical and thermal performance has been studied. An experimental investigation with three different configurations, PVT, PCM integrated PVT (PVTPCM), and MWCNT enhanced PCM integrated PVT (PVTNePCM) systems, was carried out under varying solar radiations and a water flow rate of 0.013–0.016 kg/s compared to conventional PV system. A two-step technique was employed to formulate the nanocomposites, and the energy performance of both PV and PVT systems assessed experimentally. The performance of PVTPCM and PVTNePCM systems was evaluated using the TRNSYS simulation technique. The formulated nanocomposite exhibited a 71.43% enhancement in thermal conductivity, a significant reduction in transmittance up to 92% and remained chemically and thermally stable. Integration of NePCM in the PVT system resulted in a notable decrease in panel temperature and a 25.03% increase in electrical efficiency compared to the conventional PV system. The highest performance ratio and overall efficiency for PVTNePCM were 0.55 and 81.62%, respectively, at a flow rate of 0.013 kg/s. The energy payback periods of PVTNePCM, PVTPCM, and PVT setup were 4.7, 4.8 and 5.6 years, respectively. Additionally, a significant improvement in thermal efficiency were observed for PVTPCM and PVTNePCM systems compared to water-based PVT systems, due to the energy stored in the thermal energy storage material.

A Novel Liquid–Solid Fluidized Bed of Large-Scale Phase-Changing Sphere for Thermal Energy Storage

The storage of thermal energy has been hindered by the low heat-transfer rate of the solid phase of the phase-changing materiel. With water being the heat-transfer fluid as well as the liquid phase in the liquid–solid two-phase system, a novel type of fluidized bed is designed in this study. Numerous hollow spheres are fabricated with phase-changing materiel encapsulated. Adding the solid–liquid phase-change material capsules to the flowing fluid, the capsules are dispersed suspended in the carrier. The large spheres, 25 mm in present experiment, possess the merits of guaranteeing energy-storage density and tolerating internal interface chaotic motion. Both the fluidization status and phase-changing process are recorded by photography combined with image-processing technology. It is found that the large spheres, with density less than water, can be fluidized by the downward flowing fluid. As the flow rate increases, the expansion ratio of the solid phase increases and the regimes of incipient fluidization and bubbling fluidization can be observed. In comparison to the fixed bed, the oscillation of pressure drop across a fluidized bed is more severe, but the averaged value is less than the fixed bed. The melting and solidifying can be accelerated by 22.6% and 50%, respectively, thus proving the superiority of the fluidized bed in improving the heat-transfer rate while charging/discharging the thermal energy. Three types of basic movement of the spheres are shown to contribute to the enhanced phase-changing rate, which are shifting, colliding and rotating.

A Review on the Effective Utilization of Organic Phase Change Materials for Energy Efficiency in Buildings

Energy efficiency is critical for achieving building sustainability because it means that fewer resources are consumed. In this context, the advancement of phase-changing materials has attracted attention with regard to the integration and management of energy efficiency in construction projects. Buildings consume 40% of the global energy output annually, accounting for one-third of the global greenhouse gas emissions. For hot weather-prone construction, PCMs should have a melting temperature of 25–50 °C. For more than 30 years, researchers worldwide have experimented with PCMs at various temperatures, but few studies have been conducted in hot or harsh environments. According to recent studies, the amount of PCMs in construction materials has been limited to 20%, and exceeding this ratio was shown to significantly affect the compressive strength of concrete specimens. In this study, various phase-changing concrete materials were investigated to reduce the thermal energy consumption of buildings. This paper aims to provide an overview of the current state-of-the-art phase change materials for constructing thermal energy storage building materials. It also includes a brief review of the most recent developments in phase change technologies and their encapsulation techniques based on thermophysical properties. Implementing PCM technology in buildings will also maintain good indoor air quality. These materials are widely used in various real-time applications to significantly enhance thermal comfort in buildings.

Saponification residue–sodium nitrate morphologically stable phase-change materials for medium- and high- temperature thermal energy storage

Saponification residue (SR) is a by-product of the chlor-alkali process used to produce propylene oxide. Owing to its high porosity and large specific area, SR is suitable as a carrier in the preparation of composite phase-change materials (CPCMs). This approach not only addresses the leakage issues associated with phase-change energy storage materials but also utilises solid waste. Herein, a morphologically stable CPCM was prepared using industrial SR solid waste and a phase-change material (sodium nitrate) via a hybrid sintering method. Phase analyses by X-ray diffractometer showed good chemical compatibility between sodium nitrate and SR. Further, scanning electron microscopy showed that SR has a porous structure, and sodium nitrate can be stably adsorbed on the pores and surface of SR. The maximum compressive strength of SR-CPCM was 43.37 MPa. Moreover, the highest loading capacity of SR for sodium nitrate was 50 wt%, resulting in no leakage and remarkable morphological stability. Differential scanning calorimetry indicated that SR-CPCM exhibited adequate thermal stability and that the latent heat increased with rising nitrate content, reaching a maximum value of 99.24 J/(g·°C). Importantly, after 100 thermal cycles, SR-CPCM demonstrated good stability in terms of chemical compatibility and latent heat. These results demonstrate the potential of SR as a carrier material for energy storage applications.

Numerical Modeling of Metal Hydride-Phase Change Material Hydrogen Storage Systems with Increased Heat Exchange surface area

Coupling Metal Hydrides (MH) with Phase Change Materials (PCM) provides a promising way of storing hydrogen without using any active systems to control the MH temperature during cycling. In this study, we perform numerical assessments on the performance of cylindrical MH-PCM storage systems with varying geometrical configurations. We investigate the ab/desorption kinetics in a straight cylindrical geometry (case A), where the PCM surrounds the MH. Its cycle time and gravimetric density for the absorption of 1.04kWh are 2,200 s and 0.30%. We then investigate two improved configurations, namely the addition of fins to the external surface of the MH and within the PCM domain (case B), and the containment of the MH powder into a helix-shaped tube immersed in the PCM (case C). Number and thickness of fins are also varied to assess their impact. Compared to case A, the helix-shaped design is 49% and 40% faster in absorption and desorption, respectively, whereas the finned geometry is 28.9% and 30% faster. The gravimetric density is 0.27% and 0.62% in case B and C, respectively.

Simulation and experimental analysis of PCM-enhanced solar stills using CMS

In view of their low water production capacity, solar stills require thoughtful consideration of several design and performance factors in order to achieve optimal output. The objective of this research effort is to evaluate a solar still desalination system parametrically and examine how adding phase change material (PCM) affects a single-slope solar desalination unit's efficiency. The study utilizes computational fluid dynamics (CFD) numerical modeling using COMSOL Multiphysics 5.6 software (CMS) to assess the performance of two configurations: a conventional solar still (CSS) and a solar still integrated with energy storage material (PSS). Experimental results have shown that the heat transfer rate of the solar still employing energy storage material is 20 % higher compared to the simple solar still. The daily productivity of systems utilizing PCM demonstrated significant improvements, being 2958 mL/m2-day compared to that of a simple solar still at 2185 mL/m2-day. Additionally, CMS was employed in this study to validate the simulation results with the experimental data. The economic analysis showed that adding PCM to the solar desalination system leads to a cost per liter (CPL) of 3.1 INR and a payback period of 205 days.

Multifunctional composite phase change material with electrostatic self-assembly structure based on carboxylated multi-walled carbon nanotubes

The need for improved thermal regulation in electronic devices and solar thermal energy storage, prompted by the energy crisis, has expedited the advancement of phase change materials (PCMs). Carboxylated multi-walled carbon nanotubes (MWCNT-COOH) were produced by introducing carboxyl functional groups onto MWCNTs utilizing a concentrated acid treatment. The novel composite was engineered through an electrostatic self-assembly process between the negatively charged MWCNT-COOH and the positively charged Poly dimethyl diallyl ammonium chloride (PDDA) solution, filling the structure with the PCM polyethylene glycol (PEG) and incorporating the (magnesium hydrate) Mg(OH)2 to enhance the material's flame resistance at high temperatures. The thermal conductivity of the obtained composites improved significantly from 0.25 W/m·K to 1.183 W/m·K, while maintaining an enthalpy of phase transition of phase change of 135.1 J/g. Owing to the capillary effect of the closely packed MWCNT-COOH tubular structure, the composite material exhibited excellent high-temperature shape retention ability. Additionally, the composite demonstrated high absorption with an absorbance reaching 1.18 L/(g·cm) and composite materials can convert up to 86.8 % of light energy into heat energy.

Experimental study on the charging and discharging performance of a thermal energy storage unit using low temperature phase change material

The latent heat thermal energy storage (LHTES) unit offers a versatile solution for storing waste heat and solar thermal energy across various temperature ranges. Despite its potential, limited experimental research has been conducted on LHTES units operating at low temperature ranges. This study addresses this gap by experimentally investigating the performance of an LHTES unit using water as the heat transfer fluid (HTF) and myristic acid (PCM) with a phase change temperature of 53–55 °C. The rectangular configuration of the TES unit was chosen for its practical advantages in industrial and residential applications, facilitating efficient space utilization and uniform thermal distribution. Experiments were conducted with various HTF volumetric flow rates (200, 300, and 400 LPH) using a constant temperature heat source. PCM and HTF temperature profiles at three segments of the TES unit were used to evaluate key parameters essential for designing a storage system, including thermodynamic analysis, Nusselt number, stratification analysis, storage/recovery efficiency, and charging/discharging efficiency. These parameters provide valuable insights into the performance of the LHTES unit. The outcomes indicate that increasing the HTF flow rate from 200 to 400 LPH decreases the charging/discharging duration by 40.73 % and 38.24 %, respectively. At the higher flow rate (400 LPH), convective mixing increases, reducing stratified layer stability. Furthermore, increasing the HTF flow rate leads to a reduction in peak Richardson numbers by 31.6 % and 27.8 % during charging/discharging, indicating a transition towards diminished stratification and increased turbulence in the HTF flow. In conclusion, while the TES unit exhibited better performance at a lower HTF flow rate (200 LPH), practical applications demand efficient fast charging and discharging. Despite this, minimal differences in efficiencies, energy, and exergy rates across flow rates suggest practical viability in various test conditions.

Evaluating passive PCM performance in building envelopes for semi-arid climate: Experimental and numerical insights on hysteresis, sub-cooling, and energy savings

This study evaluates the performance of macro-encapsulated Phase Change Materials (PCMs) integrated into building envelopes for semi-arid climates, focusing on typical Moroccan construction using hollow concrete blocks. The primary objective is to assess the discrepancies between experimental and numerical analyses, particularly in hysteresis, sub-cooling, and energy savings. Given the widespread reliance on numerical tools like EnergyPlus for PCM simulations, the accuracy of manufacturer-provided latent heat values is investigated. The methodology involves constructing two identical test buildings, one equipped with PCM panels and another as a reference. Experimental data were collected in June 2023, assessing temperature fluctuations and energy savings. Differential Scanning Calorimetry (DSC) tests at varying scanning rates were conducted to analyze PCM behavior, including hysteresis and sub-cooling effects. Numerical simulations were then performed to compare energy performance. Besides, the results reveal that sub-cooling significantly limits PCM efficiency, with only 43 % of the PCM's latent heat capacity utilized. At the same time, hysteresis was found to be negligible in the field test. Cooling energy consumption was reduced by 20 %, with a corresponding 2.3 °C reduction in temperature fluctuations. However, the PCM's latent heat potential is underutilized due to sub-cooling. This research underscores the need for conducting DSC measurements at specific scanning rates to reflect regional climate conditions and suggests that simulation models should adjust latent heat utilization of the PCM. The study advocates for the use of composite PCMs, which could mitigate sub-cooling and enhance overall performance. These findings contribute to improving PCM integration in passive building designs, offering practical recommendations for better energy efficiency in semi-arid climates.

An appraisal of phase change materials: characteristics, categorization, benefits, drawbacks and utilizations. A review

A new era of energy-efficient solutions has arrived thanks to the revolutionary class of substances known as phase change materials (PCMs), which have the extraordinary capacity to store and release thermal energy during phase transitions. The defining characteristics of PCMs, such as their well-defined melting and freezing temperatures, high latent heat of fusion, and variety of material types, including organic and inorganic PCMs, as well as eutectic combinations, are thoroughly examined in this thoroughly analysis. PCMs are divided into groups according to the physical shape they take and the temperature range in which they are used. These groups include low-temperature variations, high-temperature variants, encapsulated forms, and nanocomposite forms. PCMs provide a wide range of advantages, including effective thermal energy storage, cost-effective energy use, consistent temperature maintenance and small light designs. However, they do have some restrictions, such as compatibility issues and slow heat transfer rates. However, PCMs are used in a wide range of industries, from electronics and renewable energy to building and construction, revolutionizing temperature control, thermal management and energy efficiency. The future of PCM technology offers promise, with ongoing improvements aiming at improving heat transmission, integrating with renewable energy sources and enhancing encapsulation processes. This technology's vital position in a sustainable and efficient energy future is apparent, as it continues to transform our world in the hunt for responsible and green energy solutions.

Experimental and numerical investigation of a double spiral tube heat exchanger in a novel composite phase change material

Phase change energy storage technology effectively harnesses energy, and phase change materials have been garnered significant attention due to their high latent heat capacity. The heat transfer capacity and phase transition of HCNT−CH3COONa·3H2O/Na2HPO4·12H2O composites in a double spiral tube heat storage unit were investigated. The effects of different flow rates and temperatures on the heat transfer characteristics of phase change materials were studied, and the thermal performance of the storage units was evaluated by calculating the power, energy and energy efficiency ratios. The phase change process of the composite during heat transfer was further revealed via simulation, and the heat storage and heat release of the composite were compared with those of other phase change materials. The results show that the effects of the flow velocity on the transformation time and power of the phase change material are negligible. However, an increase in flow rate can significantly increase the heat storage and heat release of the phase change unit. In particular, when the flow rate is 4 LPM, the energy efficiency ratio can reach 76.6 %. When the temperature increases from 80 °C to 90 °C, the melting time decreases by 30.23 %, indicating that increasing the temperature has a significant effect on the phase transition process. Through simulation calculations, the composite phase change material shows significant performance advantages under the same working conditions; its heat storage capacity is 108 % greater than that of the other materials, and the heat release capacity is 206 % greater, which indicates that it has greater energy storage and release efficiency and a better thermal energy conversion capacity. In addition, the experimental and simulation results also reveal the existence of a diagonal region of slow phase transition in the heat storage unit. In summary, this paper analyses the heat transfer performance of a double spiral tube heat storage device, provides a theoretical basis for practical application, and provides an important reference for improving the performance of a phase–change energy storage system.

The Regulation of Temperature Fluctuations and Energy Consumption in Buildings Using Phase Change Material–Gypsum Boards in Summer

This study examined the thermal performance of Comfortboard23, a commercial gypsum board from Knauf infused with phase change material (PCM). Structural characterization using XRD and SEM confirmed the presence of microencapsulated PCM within the gypsum matrix. The study does not provide a direct comparison between Comfortboard23 and other PCM-integrated gypsum boards on the market. This is a limitation of the research. A comprehensive comparison would involve testing multiple products under identical conditions, and evaluating factors such as thermal performance, cost-effectiveness, durability, and ease of installation. Thermal characterization involved a novel low-scale thermal chamber to measure U-value, thermal conductivity, heat storage capacity, and dynamic thermal response. Results showed incorporating PCM decreased the U-value by 2% compared to standard gypsum boards. Additionally, PCM inclusion increased heat storage capacity by around 45% and improved dynamic thermal characteristics by decreasing thermal stability coefficient from 0.92 to 0.76 and increasing thermal lag from 0.27 to 0.49 h. The 45% increase in heat storage capacity of Comfortboard23 could lead to a 10–20% reduction in heating and cooling energy consumption, improved thermal comfort, and potential HVAC downsizing. Exact benefits depend on climate, building design, and occupancy patterns, necessitating further research in diverse real-world settings. The findings demonstrate Comfortboard23’s potential for enhancing thermal energy storage in buildings, contributing to energy savings, improved thermal comfort, and reduced temperature fluctuations across varying daily temperatures. Overall, the study highlights the promise of Comfortboard23 as an energy-efficient PCM-integrated building material.

Improving the charging performance of latent heat thermal energy storage systems using triply periodic minimal surface (TPMS) structures

The utilization of latent heat thermal energy storage (LHTES) using phase change materials (PCM) has attracted considerable attention due to their high energy density and thermal regulation. However, the inferior thermal conductivity of PCM has hindered their widespread implementation, triply periodic minimal surface (TPMS) structures could considerably ameliorate the energy storage utilization. TPMS structures offer escalated surface area and pore interconnectivity, which can enhance the apparent thermal conductivity and improve the performance of LHTES systems. This study focuses on investigating the performance and storage capabilities of three unique TPMS structures, namely Gyroid, IWP, and Primitive, at different relative densities and charging temperatures. The computational model is developed, verified, and validated with the relevant experiment results. A comparative analysis of the temperature distribution and liquid fraction evolution in TPMS LHTES units is carried out and compared to pure PCM LHTES. At a charging temperature of 80 °C, compared to the complete melting time of 7206 s for the pure PCM LHTES, the results demonstrate that the G10, IWP10, and P10-PCM LHTES achieve complete melting at 344 s, 276 s, and 368 s, respectively. This affirms the superiority of IWP structures in improving the melting rates due to their escalated surface areas and tortuous paths. The use of TPMS structures improves the total heat storage, heat storage rate, and volumetric heat storage density, while reducing the gravimetric heat storage density, compared to the pure PCM LHTES. The G10-PCM LHTES attains total heat storage, heat storage rate, volumetric, and gravimetric heat storage density of 2120 J, 6.16 W, 63.6 kWh/m3, and 227 kJ/kg, compared to 1910 J, 0.27 W, 57.3 kWh/m3, and 250 kJ/kg for pure PCM LHTES, respectively. Moreover, increasing the relative density of TPMS structures adversely reduces the total heat storage, heat storage rate, and volumetric heat storage density, and significantly increases the heat storage rates. As the charging temperature increases, the complete melting time is reduced and the charging performance indicators are improved, for the pure PCM and TPMS-PCM LHTES units.

Optimization of coupling phase-change materials and thermal screens in façade-integrated hybrid photovoltaic collectors for optimal energy production and thermal comfort in buildings

The operation of building-integrated photovoltaic (BIPV) systems gives rise to a significant proportion of the solar radiation absorbed by the cells being unable to be converted into electricity. This phenomenon consequently increases the temperature. This temperature increase impacts the cells' electrical efficiency, leading to a reduction in their performance and accelerating their degradation. The combination of phase-change materials with insulating fluid blades, situated behind photovoltaic cells, represents a passive cooling solution that optimizes the performance of hybrid photovoltaic systems when incorporated into facades. The present study assesses a system that incorporates paraffin as a PCM and an argon layer in a PV-PCM-argon layer physical model (PVT/ArPCM), in comparison with a PV-PCM system (PVT/PCM), to enhance the thermoelectric performance of photovoltaic systems mounted on façades while ensuring optimal thermal comfort within buildings. The discrete heat transfer equations were solved using the Thomas algorithm and the iterative Gauss-Seidel method in conjunction with the implicit finite difference method. The findings illustrate that the electrical efficiency experienced only a slight increase, estimated at 0.01%, while there was a notable enhancement in the indoor thermal comfort experienced by occupants, with a 65% improvement observed due to the incorporation of an argon-filled thermal screen. The incorporation of an argon layer led to a minor reduction in temperature of 0.01°C in the photovoltaic cells, resulting in a minimal improvement of 0.014% in electrical power production. The phase-changing material incorporated into PVT/ArPCM demonstrated superior thermal management capabilities in comparison to the same material employed in PVT/PCM.

Laser-induced reconfigurable wavefront control with a structured Ge2Sb2Te5-based metasurface

Phase change materials have been widely exploited in active metasurfaces due to their large index contrast. Despite recent advances in phase-change metasurfaces, it remains a challenge to integrate diverse reconfigurable optical functionalities into a single metasurface. Here, we demonstrate an effective strategy to realize reconfigurable wavefront control by combining a Ge2Sb2Te5-rod array with laser writing technology. Through arbitrarily modifying the position and power of laser source, the laser writing process helps to realize site-selective and multi-level phase change of Ge2Sb2Te5 rods. Due to multi-level switching for optical properties of Ge2Sb2Te5 material, the Ge2Sb2Te5-rod array offers complete phase control and high amplitude modulation. Subsequently, various optical devices are designed in numerical simulation, including a phase-only hologram, dynamic meta-deflectors, a grayscale image and a perfect absorber. The structured Ge2Sb2Te5-based metasurface with the combination of laser writing technology offers an effective way to explore various types of optical functionalities in the same device.

Research and Case Application of Zero-Carbon Buildings Based on Multi-System Integration Function

This study focuses on developing and implementing zero-carbon buildings through the integration of multiple systems to meet China’s carbon neutrality goals. It emphasizes the significant role of the building sector in carbon emissions and highlights the challenge of increasing energy consumption conflicting with China’s “dual carbon” targets. To address this, the research proposes a comprehensive framework that combines multifunctional envelope structure (MES) systems, photovoltaic power generation, energy storage, direct current (DC) systems, flexible energy management (PEDF), and regional energy stations. This framework integrates different technologies such as phase change materials, radiation cooling, and carbon mineralized cement, aiming to reduce carbon emissions throughout the building’s lifecycle. The method has been successfully applied in the Yazhou Bay Zero Carbon Post Station project in Sanya, Hainan, with precise calculations of carbon emission reductions. The carbon emission calculations revealed a reduction of 44.13 tons of CO2 annually, totaling 1103.31 tons over 25 years, primarily due to the rooftop photovoltaic systems. It demonstrates that the multi-system integration can reduce carbon emissions and contribute to China’s broader carbon neutrality goals. This approach, if widely adopted, could accelerate the transition to carbon-neutral buildings in China.

Active infrared tuning of metal–insulator-metal resonances by VO2 thin film

VO2 is a promising phase change material offering a large contrast of electric, thermal, and optical properties when transitioning from semiconductor to metallic phase. Here we show that a hybrid metamaterial obtained by proper combination of a VO2 layer and a nanodisk gold array provides a tunable plasmonic gap resonance in the infrared range. Specifically, we have designed and fabricated a metal–insulator-metal gap resonance by inserting sub-wavelength VO2 film between a flat gold layer and a gold nanodisk resonator array. The resonance of the hybrid metamaterial is centered in the useful 3–5 μm range when VO2 is in its semiconductor state. The experimental study highlights a monotonical spectral tuning of the resonance when increasing temperature up to 50 °C above the room temperature, providing a continuous resonance shift of almost 1 μm in the mid-infrared range. Wavelength range and intensity tunability can be further optimized by modifying the thicknesses of the layers and metamaterial parameters.