Solar Energy Harvesting Applications Research Articles

Sequential Infiltration Synthesis of Cadmium Sulfide Discrete Atom Clusters.

Exposure of soft material templates to alternating volatile chemical precursors can produce inorganic deposition within the permeable template (e.g. a polymer thin film) in a process akin to atomic layer deposition (ALD). While such sequential infiltration synthesis (SIS) processes have now been demonstrated for many metal oxides, we report an SIS process for a transition metal sulfide - CdS. Gas phase dimethyl cadmium and hydrogen sulfide precursors infiltrated into poly(4-vinylpyridine) thin films result in the 3D-nucleation of clusters consistent with a cubane-type Cd4S4 core that are variably terminated with methyl, thiol and hydroxy capping ligands. First principles models and simulation of few-atom Cd-based clusters are consistent with electronic and vibrational spectroscopy and grazing-incidence total X-ray scattering measurements of 3D-cluster-arrays synthesized at 80 °C. The direct synthesis of few-atom transition metal sulfide clusters within polymer thin films will provide a versatile new route to precision architectures for light-absorbing materials including solar energy harvesting and conversion applications.

Sequential Infiltration Synthesis of Cadmium Sulfide Discrete Atom Clusters

AbstractExposure of soft material templates to alternating volatile chemical precursors can produce inorganic deposition within the permeable template (e.g. a polymer thin film) in a process akin to atomic layer deposition (ALD). While such sequential infiltration synthesis (SIS) processes have now been demonstrated for many metal oxides, we report an SIS process for a transition metal sulfide – CdS. Gas phase dimethyl cadmium and hydrogen sulfide precursors infiltrated into poly(4‐vinylpyridine) thin films result in the 3D‐nucleation of clusters consistent with a cubane‐type Cd4S4 core that are variably terminated with methyl, thiol and hydroxy capping ligands. First principles models and simulation of few‐atom Cd‐based clusters are consistent with electronic and vibrational spectroscopy and grazing‐incidence total X‐ray scattering measurements of 3D‐cluster‐arrays synthesized at 80 °C. The direct synthesis of few‐atom transition metal sulfide clusters within polymer thin films will provide a versatile new route to precision architectures for light‐absorbing materials including solar energy harvesting and conversion applications.

Kirchhoff's law violation within the main solar wavelength range

Recently, nonreciprocal structures that violate Kirchhoff's law of thermal radiation have attracted considerable interest for their potential in solar energy harvesting applications. However, previous research has primarily focused on mid-infrared wavelengths rather than on the main solar wavelength range where sunlight intensity is concentrated. In this work, we theoretically demonstrate a nonreciprocal structure operating within the main solar spectrum, specifically tailored to meet the requirements of solar cell applications.

Engineering plasmonic charge kinetics and broadband photoelectrochemical spectral responses using a multi-resonant Au-TiO2 plasmonic particle grating-based optical resonator.

The plasmonic integrated semiconductor has widened the operational spectral region of semiconductors for light-matter interaction-driven solar energy harvesting applications. However, a specific plasmonic resonance has moderate light absorption and is only active in a specific width of the visible spectrum. We present a tailored plasmonic particle grating-based Au-TiO2 Schottky photoelectrode-based broadband absorber that operates in the extended spectral region of 400-800 nm due to the synergistic interaction of multi-resonant photonic and plasmonic modes of the plasmonic particle grating structure. In the visible spectrum, the proposed photoelectrode increased the incoming photon to electron conversion efficiency (IPCE%) by seven and five times more than TiO2 for TM (along the grating vector) and TE (perpendicular to the grating vector) incidence, respectively. The plasmonic response of the gold nanoparticle and the grating-coupled surface plasmon polariton (SPP)-guided mode resonance (GMR) are responsible for such increments. Ultrafast pump-probe spectroscopy verifies that the plasmon-GMR interaction causes extended plasmonic charge generation and lifetime. The kinetics of plasmonic-generated charges in grating-coupled SPP and LSPR was investigated through TM and TE polarized pump and probe excitation. Such findings are consistent with the observed PEC spectral responses under their respective polarization illumination. Therefore, our research provides a simple method for integrating photonic and plasmonic materials for innovative broadband spectrum responses in photovoltaic and energy harvesting applications.

Concentrated near-field thermophotonics for efficient solar energy harvesting: Model development, system analysis, and performance optimization

In recent years, research on near-field thermophotonic systems has predominantly focused on waste heat recovery and electroluminescence cooling, while studies on near-field thermophotonic converters for solar energy harvesting have not been reported. We propose a near-field solar thermophotonic converter (NF-STC) that harnesses the full solar spectrum to generate electricity. Considering fluctuational electrodynamics and nonradiative recombination losses, we developed a self-consistent model to theoretically evaluate the performance of the NF-STC system from far-field to near-field regimes under two scenarios: varying LED temperature and fixed LED temperature. In the case of variable LED temperature, we identify that increasing the solar concentration, decreasing the thickness of the semiconductor material to mitigate the effect of non-radiative recombination, narrowing the vacuum gap spacing, and implementing gold back reflector for photon recycling can significantly bolster the performance of the system. Specifically, when the gap spacing is 10 nm, and the solar concentration factor is 400, we show that the total electrical power density and overall conversion efficiency can reach 8892 mW cm−2 and 22.2%, respectively. Conversely, in the fixed LED temperature scenario, the performance characteristics diverge from those observed in the variable temperature case. The system exhibits superior performance at higher LED temperatures and smaller gap spacing. This work deepens the understanding of thermophotonic converters’ application in solar energy harvesting by considering the interplay of various physical phenomena. It presents a promising pathway for efficient solar thermal power conversion.

Metamaterial absorber with ultra-broadband, ultra-high absorption, polarization independence and high-temperature resistance for solar thermal energy harvesting applications

In this work, a metamaterial absorber with ultra-broadband, ultra-high absorption, polarization independence and high-temperature resistance for solar thermal energy harvesting applications is designed and numerically simulated. The proposed nanostructure is composed of four T-shaped strips and square ring nanoarray structures of tungsten (W) material deposited on Au substrate. The findings demonstrate that the solar metamaterial absorber can attain broadband absorption of solar energy with a bandwidth of 1.78 μm and the absorption rate of over 90% at the resonance wavelengths of 0.4 μm and 2.18 μm. Namely, the solar absorber exhibits excellent features of ultra-broadband and ultra-high absorption. The ultra-broadband and ultra-high absorption rate of solar absorbers are achieved by exciting surface plasmon resonance (SPR). In the design of solar absorber, the performance can be further enhanced by optimizing the geometry of the nanostructure (e.g., changing the geometric dimensions of T-shaped strips and square rings, and the period of array structures, etc.). Whether in TM mode or TE mode, solar metamaterial absorbers are insensitive to incident angles and can be used within the range of 0°–45° incident angles. The variation of the polarization angle also does not affect the absorption performance of the solar absorber with good polarization independence. Furthermore, at high temperatures from 300 °C to 1500 °C, the optical properties hardly change. It is found that the designed solar metamaterial absorber not only has ultra-broadband and ultra-high absorption, but also has excellent performance of polarization independence and high-temperature resistance. Consequently, this absorber has a promising application in solar cells, photothermal conversion and solar thermal energy harvesting applications.

Multi-layer nanoring array-based ultra-wideband solar absorber for photothermal conversion

In this work, based on the finite difference time domain method, we propose and investigate an efficient nanoscale solar absorber based on multilayer nanorings. The absorber is made up of a 4-layer TiO2-TiN nanoring array, a TiO2 insulating layer and a Ti substrate, all of which are high-melting materials. The absorber exhibits an absorption efficiency surpassing 95 % across a wavelength span of 280–4000 nm, thereby attaining a bandwidth of 3720 nm. Additionally, it maintains an average absorption efficiency of 98.8 % throughout the entire wavelength spectrum. Furthermore, calculations reveal that the absorber possesses a solar spectrum-weighted absorption of up to 99 %. The analysis of the electric field distribution indicates that the observed intense absorption is attributed to the plasmonic resonance phenomenon, along with the near-field coupling effects exhibited by the multi-turn nanorings. In addition, our calculations revealed a remarkably high thermal radiation efficiency for this absorber, specifically 99.2 % at 2000 K and 98.9 % at 1500 K, respectively. Therefore, we then calculated the photothermal conversion efficiency of the absorber. At the solar concentration factor C = 1000, the photothermal conversion efficiency surpasses 90 % across the entire temperature range. At C = 100, it is still greater than 80 % at 1000 K. At C = 10, it is still greater than 80 % at 700 K. And at C = 1, it is still greater than 80 % at 500 K. These results indicate that absorbers can be used in a variety of environments. Furthermore, the absorber sustains its superior absorption capabilities at wider solar radiation angles, demonstrating insensitive properties to polarization variations and robust tolerance to manufacturing inaccuracies. These exceptional attributes render it highly suited for diverse applications in solar energy harvesting and photothermal transformation.

Band gap engineering of novel double perovskites Na2LiYX6 (X=Cl, Br) through halide ion replacement for solar cell and energy harvesting applications

Using the Perdew − Burke − Ernzerhof-generalized-gradient approximation (PBE-GGA) and PBE+SOC exchange − correlation functional, this work investigates the physical properties and energy storage capacity of novel double perovskite Halides Na2LiYX6 (X=Cl and Br) through Density Functional Theory (DFT) and semiclassical transport theory under ideal conditions. Thermal stability has been verified through the computation of thermodynamic parameters and formation energies. Brittle and anisotropic nature has been confirmed by the calculation of elastic and mechanical parameters. With PBE+SOC, the band gaps (Eg) for Na2LiYCl6 and Na2LiYBr6 are 2.90 and 3.76 eV, respectively, whereas with PBE-GGA, they are 3.061 and 3.824 eV, respectively. The analysis of the computed optical characteristics determines whether double perovskite halides are suitable for use in photovoltaic applications. The calculations for the transport properties were carried out using the BoltzTraP code. The effectiveness and transport mechanism for thermal energy conversion have been studied by determining the thermoelectric properties. To assess the stability at high temperatures and suitability for industrial applications, thermal properties such as heat capacity, entropy, Debye temperature, and thermal expansion are investigated. Overall, evaluations of the compounds’ thermoelectric characteristics show that they have a high-power factor and remarkably low thermal conductivity, which makes them ideal for energy harvesting devices.

Tuning of optical, thermodynamic, and thermoelectric properties of Cs2CuBiX6 (X = Cl, Br, I) halide perovskites for solar cells and energy harvesting applications

The double perovskites are outstanding materials for solar cells and transport applications to clean harvest energy. Therefore, the Cs2CuBiX6 (X = Cl, Br, I) are discussed comprehensively for energy harvesting by modified Becke and Johnson (mBJ) potential. The studied DPs fit the structural, mechanical, and dynamic stability scale by tolerance factor, Born–Huang criteria, and phonon dispersion band structures. The band gaps (1.20, 1.0, 0.70) eV for (Cl, Br, I) based DPs ensure the Cs2CuBiCl6 has an absorption band in the visible region while Cs2CuBiBr6 and Cs2CuBiI6 has an absorption band in the infrared region. Heavy elements’ spin–orbit coupling effect (Cs, Bi) reduces the band gap to 0.08 eV. Thermoelectric behavior regarding the merit scale against dopant carriers and temperature has been elaborated. The ultralow lattice thermal conductivity, large Debye temperature, hardness, and melting temperature increase their implication for thermoelectric and other thermodynamic applications. The variation in band gap makes them important for diverse optoelectric and thermoelectric applications. The Cs2CuBiCl6 with a band gap of 1.20 eV is suitable for solar cells, while Cs2CuBiBr6 and Cs2CuBiI6 with band gaps of 1.0 eV and 0.70 eV are significant for thermoelectric generators.

Tunable distributed Bragg reflector developed by magnetron sputtering to improve the power conversion efficiency of transparent IR cells for solar energy harvesting applications

Transparent organic photovoltaic (TOPV) cells integrated into windows are key to reducing the carbon dioxide emissions associated with the building sector. However, TOPV cells that reach a compromise between efficiency and transparency must still be developed. In addition, to implement this technology in glass production companies, the materials and processes used in TOPV cell development must be compatible with producing these devices on an industrial scale. Here, an infrared (IR) cell combining a PC60BM-based active material, ITO/ZnO as the back transparent electrode, PEDOT:PSS and ITO or Ag as the top transparent electrode, and a DBR as an antireflective coating was developed and applied on 625 mm2 glass samples. The structure of the DBR based on titanium dioxide (TiO2) and silicon dioxide (SiO2) monolayers was adjusted to the IR cell absorption spectra to reach a power conversion efficiency (PCE) of 5 and 4.3, and an average visible transmission (AVT) of 41 % and 51 % for ITO and Ag top electrodes, respectively. The manufacturing route of these devices involved commercial polymers and coatings that can be deposited by technologies already applied in the glass industry, such as magnetron sputtering or thermal evaporation. Therefore, the IR cells developed here showed a good compromise between efficiency, transparency, and large-scale production manufacturability.

Study of phase Stability, Optical, and thermoelectric properties of antiperovskites X3GeO (X=Ca, Sr, Ba) for solar cells and energy harvesting

Perovskites and their inverse derivatives are emerging aspirants for solar cells and energy harvesting applications. Herein, we have comprehensively addressed the phase stability, optical, and transport characteristics of X3GeO (X=Ca, Sr, Ba) antiperovskites by first-principles analysis. The studied compounds have an orthorhombic crystal structure with a space group (1-P1). The phonon spectra have been computed to assess the dynamic stability. The electronic band structures demonstrate that perovskites have narrow band gaps, while the antiperovskites are narrow band gap semiconductors. The calculated values of band gaps for antiperovskites are 0.38, 0.63, and 0.70 eV, respectively, suggesting optimal absorption in infrared to visible regions. Light energy’s dispersion and absorption are calculated by a complex dielectric function, refractive index, and absorption coefficient in the energy range 0 to 5 eV. The Seebeck coefficient, electrical & thermal conductivities, and power factor assess thermoelectric performance at increasing temperatures and carrier concentration. The findings convey a theoretical foundation for future experimental investigations of these antiperovskites and suggest their effectiveness for optoelectronic, and thermoelectric applications to harvest green energy.

Quasi-conformal monolithic n-i-p perovskite/c-Si tandem solar cells with light management strategies exceed 28 % efficiency

In the rapidly evolving field of photovoltaic technology, monolithic perovskite/crystalline silicon tandem solar cells (PSK/c-Si TSCs) have emerged as promising contenders, combining the advantageous properties of PSK with the recognized power conversion efficiency (PCE) of c-Si. Available studies have shown that in the field of PSK/c-Si TSCs, c-Si substrates can be categorized into: flat and pyramidal-textured structures. The limitation of flat structure lies in optical reflection losses, and the commercialization of large-scale pyramid structure is challenging to be compatible with conventional planar PSK solution processes. This study presents a novel quasi-conformal structure with dimensions between flat and pyramidal structures, which facilitates its seamless integration into PSK and c-Si production. Thermally evaporated bis(trifluoromethane)sulfonimide (TFSI)-doping 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9′-spirobifluorene (spiro-OMeTAD) has better conformal and electrical properties. The in-situ cesium-based PSK recrystallized-arrays (CPRA) growth scheme achieves current density matching of the two sub-cells by band-edge modulation of the wide-bandgap components. The champion PCE of CPRA-modified PSK/c-Si TSC is 28.53 %. The stability is enhanced due to the protective effect of the inorganic CPRA interface. This research exhibits the successful integration of novel structural elements and light management strategies, which are expected to have wider applications in solar energy harvesting.

Study of Lithium-Based Double Perovskites Halides Li2AgBiZ6 (Z = Cl, Br, I) as Emerging Aspirant of Solar Cells and Energy Harvesting Applications

Study of Lithium-Based Double Perovskites Halides Li2AgBiZ6 (Z = Cl, Br, I) as Emerging Aspirant of Solar Cells and Energy Harvesting Applications

Wideband, polarization-insensitive rectangular-shaped with thin wire MXene-based resonator solar absorber for solar energy harvesting application

Solar absorbers are used in many different applications to collect solar energy. The Rectangular-Shaped with Thin Wire MXene-based resonator (RSWTWMR) is a unique solar absorber design that is proposed in this study. Aluminium and MXene are the materials used in the substrate and resonator layers of the RSWTWMR, respectively. MXene allows for the absorption of a large amount of solar light because of its remarkable absorption qualities and unique optical properties. The MXene-based resonator has a unique design with a thin wire and a rectangular box that makes it insensitive to polarization. RSWTWMR shows an astounding 95.67 % average absorption over three different wide bands. It is noteworthy that the absorption values in the 920 nm and 720 nm bandwidths exceed 90 % and 94 %, respectively. In addition, the absorption is more than 96 % at wavelengths of 550 nm. Additional research examined how well the system performs in air mass (AM1.5) conditions and examined how different factors, such as substrate and resonator thickness, affect absorption properties. Furthermore, the research looks at the impact of an angle of incidence, which is unaffected between 0 and 70°. This study suggests the RSWTWMR solar absorber has great promise for applications in solar energy harvesting.

Nano-structured metamaterial absorber based on a plus-shaped resonator for optical wavelength applications

Metamaterial absorbers have sparked widespread interest due to their remarkable electromagnetic properties, which enable a wide range of applications in light absorption and manipulation. This study introduces a new three-layer nanomaterial absorber (NMA) unit cell composed of nickel (Ni), silicon dioxide (SiO2), and nickel (Ni) designed to operate across the entire visible spectrum (390–780 nm). We demonstrate the NMA’s exceptional absorption characteristics through rigorous numerical simulations using industry-standard software, achieving a mean absorption rate of 97.17% and a maximum absorption peak of 99.99% at 694.89 nm under standard angles. Furthermore, the NMA unit cell has good impedance matching, efficient coupling between capacitors and inductors, and significant plasmonic resonance properties. Fabrication feasibility and potential applications in solar energy harvesting, optical sensing, and light detection.

Photoluminescence Measurement of Triplet Sensitizer-Emitter Solution Using a Customized 3D-Printed Sample Holder

This study explores the photoluminescence (PL) measurement of triplet sensitizer-emitter (TSE) solutions using a custom 3D-printed sample holder, within the context of triplet-triplet annihilation based molecular photon upconversion (TTA-UC) systems targeting the Vis-to-UV spectral region. TTA-UC converts low-energy visible photons to higher-energy ultraviolet (UV) photons, holding promise for solar energy harvesting and photonics applications. Two TSE couples, 4CzIPN/TP and 4CzIPN/QP, were investigated, and their upconverted fluorescence spectra showed peaks at 344 nm and 354 nm / 370 nm, respectively, confirming efficient upconversion capabilities. The 3D-printed sample holder facilitated reproducible PL measurements, enabling the calculation of quantum yields (ΦUC). The 4CzIPN/TP and 4CzIPN/QP couples exhibited low quantum yields (0.028% and 0.043%, respectively), suggesting the need for improved deoxygenation methods to enhance the triplet-triplet annihilation process and overall quantum efficiency. Despite modest yields, successful UV upconverted fluorescence observation underscores the feasibility of the Vis-to-UV TTA-UC system. This study provides insights into TTA-UC optimization and demonstrates the utility of the 3D-printed sample holder for affordable and precise PL measurements, paving the way for future advancements in photonics and solar energy applications.

Nanoscale Cu2ZnSnSxSe(4−x) (CZTS/Se) for Sustainable Solutions in Renewable Energy, Sensing, and Nanomedicine

The importance and breadth of applications of the family of quaternary chalcogenides with the formula Cu2ZnSnSxSe(4−x) (CZTS/Se) where x = 0–4 are steadily expanding due to the tunable optoelectronic properties of these compounds and the Earth abundance of the elements in their composition. These p-type semiconductors are viewed as a viable alternative to Si, gallium arsenide, CdTe, and CIGS solar cells due to their cost effectiveness, Earth’s crust abundance, and non-toxic elements. Additionally, CZTS/Se compounds have demonstrated notable capabilities beyond solar cells, such as photoelectrochemical CO2 reduction, solar water splitting, solar seawater desalination, hydrogen production, and use as an antibacterial agent. Various routes have been explored for synthesizing pure CZTS/Se nanomaterials and significant efforts have been dedicated to reducing the occurrence of secondary phases. This review focuses on synthetic approaches for CZTS/Se nanomaterials, with emphasis on controlling the size and morphology of the nanoparticles and their recent application in solar energy harvesting and beyond, highlighting challenges in achieving the desired purity required in all these applications.

Spatially Resolved Anion Diffusion and Tunable Waveguides in Bismuth Halide Perovskites.

Bismuth halide perovskites are widely regarded as nontoxic alternatives to lead halide perovskites for optoelectronics and solar energy harvesting applications. With a tailorable composition and intriguing optical properties, bismuth halide perovskites are also promising candidates for tunable photonic devices. However, robust control of the anion composition in bismuth halide perovskites remains elusive. Here, we established chemical vapor deposition and anion exchange protocols to synthesize bismuth halide perovskite nanoflakes with controlled dimensions and variable compositions. In particular, we demonstrated the gradient bromide distribution by controlling the anion exchange and diffusion processes, which is spatially resolved by time-of-flight secondary ion mass spectrometry. Moreover, the optical waveguiding properties of bismuth halide perovskites can be modulated by flake thicknesses and anion compositions. With a unique gradient anion distribution and controllable optical properties, bismuth halide perovskites provide new possibilities for applications in optoelectronic devices and integrated photonics.

Reversible Ligand Detachment from CdSe Quantum Dots Following Photoexcitation.

The nanocrystal-ligand boundaries of colloidal quantum dots (QDs) mediate charge and energy transfer processes that underpin photochemical and photocatalytic transformations at their surfaces. We used time-resolved infrared spectroscopy combined with transient electronic spectroscopy to probe vibrational modes of the carboxylate anchoring groups of stearate ligands attached to cadmium selenide (CdSe) QDs that were optically excited in solid nanocrystal films. The vibrational frequencies of surface-bonded carboxylate groups revealed their interactions with surface-localized holes in the excited states of the QDs. We also observed transient and reversible photoinduced ligand detachment from CdSe nanocrystals within their excited state lifetime. By probing both surface charge distributions and ligand dynamics on QDs in their excited states, we open a pathway to explore how the nanocrystal-ligand boundary can be understood and controlled for the design of QD architectures that most effectively drive charge transfer processes in solar energy harvesting and photoredox catalysis applications.

Ultra-broadband and wide-angle plasmonic absorber based on all-dielectric gallium arsenide pyramid nanostructure for full solar radiation spectrum range

Broadband and plasmonic absorbers (PAs) are key components for numerous applications in the fields of energy harvesting, thermal photonics, optoelectronic devices, and enhanced spectroscopy. In this work, we propose a simple and cost-effective metamaterial plasmonic absorber (MPA) design based on an all-dielectric GaAs pyramid nanostructure for the full solar radiation spectrum range. Simulation results demonstrate that the absorbance of the proposed MPA exceeds 85% in the full solar spectrum range, and it exceeds 90% from 0.25 μm to 3.1 μm with a relative bandwidth of approximately 170.74%, with an absorption peak up to 99% at resonance wavelength. The high absorption is attributed to the excitation of wave-guide mode, surface plasmon polariton (SPP) resonance modes combined with coupling effect and intrinsic lossy of dielectric GaAs and metallic tungsten (W). Furthermore, the proposed MPA is polarization-independent and wide incident angles for both transverse electric (TE) and transverse magnetic (TM) modes. Additionally, the MPA can tolerate certain structural parameter errors during practical fabrication applications. Furthermore, the photophysical properties of this MPA for solar cell applications are investigated, revealing the achievement of high short-circuit current density. Our proposed design is highly promising for applications in solar energy harvesting, thermoelectric, and thermal emitter applications.