Article
Physics, Multidisciplinary
Seyed Mohsen Mohebbi Nodez, Masoud Jabbari, Ghahraman Solookinejad
Summary: In order to enhance the absorption in the near-infrared region, a new technique using multiple gratings on the backside of the cell has been presented in this paper. The gratings on the backside lead to absorption enhancement by exciting localized surface plasmons and light scattering. By accurately determining the dimensions of the gratings, the resonance wavelength of surface plasmons can be adjusted. Multiple gratings increase the absorption in the near-infrared region near three folds, and the highest average absorption of 68.46% has been achieved using five gratings.
Article
Optics
Zeynep Durmaz, Sebastian Husein, Rebecca Saive
Summary: The concept of interference solar cells relying on spectrum filtering or splitting to enhance absorption in thin silicon absorber layers was presented. By fine-tuning device layer thicknesses, absorption enhancement in the long wavelength regime can be achieved, and when combined with spectrum splitting optics, it is also suitable for broadband absorption enhancement. An example of silicon heterojunction solar cells demonstrated a significant short circuit current density enhancement compared to traditional cells.
Article
Optics
Jun Zhu, Guangming Jin
Summary: In this article, a new type of CdTe thin-film solar cell based on a CdTe/CdS heterojunction is proposed. Simulation results show that the light absorption rate of the cell is significantly enhanced by adding h-BN and metal particles to the structure. This study provides a basis for theoretical research and feasible solutions for the manufacture of thin-film solar cells with a high absorption rate and high efficiency.
Article
Chemistry, Physical
Saurabh Pareek, Sobia Waheed, Supravat Karak
Summary: We report a systematic study on the utilization of graphitic carbon nitride nanosheets (g-C3N4 NS) thin film as a charge-selective cathode/anode interface layer for inverted and conventional polymer solar cells. The g-C3N4 NS thin film demonstrated dual functionality in terms of charge-selectivity, exhibiting similar short circuit current density for both inverted and conventional device architecture. The power conversion efficiencies for the two devices were approximately 5.60% and 6.05%, respectively. Our results demonstrate the dual functional nature of g-C3N4 NS as an interface layer for solution-processable polymer solar cells.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Gyanendra Kumar Maurya, Vidushi Gautam, Faizan Ahmad, Roshani Singh, Kavindra Kandpal, Rachana Kumar, Mahesh Kumar, Pramod Kumar, Akhilesh Tiwari
Summary: This work presents a study on the thin film of TlBiSe2, a quasi-2D topological insulator, and its heterojunctions with Glass and Si fabricated by thermal coating. Raman spectroscopy was used to identify the vibrational modes in the heterojunctions, with the identification of the surface phonon mode in the TlBiSe2/Si heterojunction. The ultrafast dynamics of charge carriers in these heterojunctions were also investigated. The study discovered the interface phenomenon in the TlBiSe2/Si p-n heterojunction. This research provides important insights for the implementation of next-generation topological insulator-based photodetectors.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Zhelu Hu, Maria Ujue Gonzalez, Zhuoying Chen, Patrick Gredin, Michel Mortier, Antonio Garcia-Martin, Lionel Aigouy
Summary: Recent studies have explored the use of up-converting fluorescent nanocrystals to improve the performance of solar cells. This work investigates the effect of nanostructuration of perovskite thin films on the optical properties of hybrid solar cells. The results show that the ideal position for the nanocrystals is between the grooves, and deeper grooves result in higher luminescence enhancement.
NANOSCALE ADVANCES
(2022)
Article
Chemistry, Physical
Jun Ma, Yujie Yuan, Ping Sun
Summary: This study successfully synthesized large-scale MoS2 monolayers using a novel method and applied them at the graphene/n-Si interface, significantly enhancing the photovoltaic conversion efficiency of graphene-based solar cells, providing a promising new approach for the application of next-generation photovoltaic devices.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Physics, Multidisciplinary
Maedeh Rassekh, Reza Shirmohammadi, Roghayeh Ghasempour, Fatemeh Razi Astaraei, Saber Farjami Shayesteh
Summary: This study investigates how different shapes of aluminum nanoparticles affect absorption enhancement in silicon thin-film solar cells, showing that using these particles can achieve over 30% conversion efficiency. While spherical particles have the highest absorption peak, optimization of parameters such as height and distance from the substrate can increase absorption.
Article
Chemistry, Multidisciplinary
Yeasin Arafat Pritom, Dipayon Kumar Sikder, Sameia Zaman, Mainul Hossain
Summary: In this study, we used metallic gold nanoparticles to enhance the light absorption of ultra-thin silicon solar cells. Through simulations, we showed that the combination of periodic and parabola shaped silicon nanostructures, along with the decoration of gold nanoparticles, can significantly improve the absorption efficiency of the solar cells. The results suggest that this approach has the potential to achieve a high conversion efficiency of 21.39%.
NANOSCALE ADVANCES
(2023)
Article
Chemistry, Multidisciplinary
Yeasin Arafat Pritom, Dipayon Kumar Sikder, Sameia Zaman, Mainul Hossain
Summary: In this study, the light absorption properties of sub-wavelength plasmonic nanostructures decorated with metallic nanoparticles are demonstrated. The parabolic shape of the nanostructures provides excellent antireflection effects, while the metallic nanoparticles offer broadband absorption and high conversion efficiency. The proposed solar cell shows a power conversion efficiency as high as 21.39%, making it a promising candidate for the next generation of highly efficient, ultra-thin, and low-cost Si solar cells.
NANOSCALE ADVANCES
(2023)
Article
Multidisciplinary Sciences
Wenjian Chen, Hippolyte Hirwa, Joerg Ohland, Teoman Taskesen, Ulf Mikolajczak, Devendra Pareek, Juergen Parisi, Levent Guetay
Summary: By depositing thin diffusion barrier layers of silicon oxynitride (SiOxNy) on Mo layers before growing CZTSe absorbers, the thicknesses of MoSe2 layers can be controlled, resulting in a reduction in thickness. CZTSe solar cells grown on Mo/SiOxNy back contacts exhibit deteriorated energy conversion efficiency as the SiOxNy layers become thicker, while those grown on Mo/SiOxNy/Mo back contacts maintain efficiencies at around 11% with thin 10 nm SiOxNy layers.
Article
Chemistry, Physical
Saurabh Kumar, Aman Choudhary, Sudeep Baudha
Summary: In this study, an efficient structure of thin film solar cell (TFSC) was designed and investigated using a plasmonic nanoantenna to improve solar cell performance. The proposed design, in the shape of a Swastika, is formed by bending a conventional dipole antenna to optimal lengths. The designed antenna is positioned on top of the absorber layer made of amorphous silicon, and an anti-reflection layer of Indium Tin Oxide is added. The Swastika-shaped structure enables equal response to different polarized waves, making it polarization-insensitive and significantly enhancing the performance of thin-film solar cells. The design also increases absorption by confining the electric field in a larger area with additional feed gaps produced by bending the dipole antenna. Simulation results show a 99.2% absorption enhancement in the absorber layer.
Article
Energy & Fuels
Sergio Giraldo, Robert Fonoll-Rubio, Zacharie Jehl Li-Kao, Yudania Sanchez, Lorenzo Calvo-Barrio, Victor Izquierdo-Roca, Alejandro Perez-Rodriguez, Edgardo Saucedo
Summary: Kesterite Cu2ZnSn(S,Se)(4) thin film technology is a promising low-cost solution in the field of photovoltaics, but efficiency improvement remains a challenge. This study introduces an innovative approach using ultrathin CuGa layers at the rear interface to enhance kesterite crystallinity and shows significant enhancement in photovoltaic performance.
PROGRESS IN PHOTOVOLTAICS
(2021)
Article
Materials Science, Multidisciplinary
Salaheddine Moujoud, Bouchaib Hartiti, Samira Touhtouh, Salah Fadili, Ali Faddouli, Fouad Belhora, Mohamed Stitou, Abdelowahed Hajjaji
Summary: This study investigated several effects on the performance of CuSbS2 based solar cells, including buffer layer thickness, carrier density, temperature effect, work function, and conduction band offset. Cadmium free solar cells were designed, with an efficiency of 16.21%.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Hongling Guo, Rutao Meng, Gang Wang, Shenghao Wang, Li Wu, Jianjun Li, Zuoyun Wang, Jiabin Dong, Xiaojing Hao, Yi Zhang
Summary: The bandgap-graded absorber layer was successfully realized in the CZTSSe film through sufficient annealing during the deposition of an Al-doped ZnO film, promoting solid-state ion-exchange reaction at the heterojunction interface.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Nikita Nefedkin, Ahmed Mekawy, Jonas Krakofsky, Yongrui Wang, Alexey Belyanin, Mikhail Belkin, Andrea Alu
Summary: Engineered intersubband transitions in multi-quantum well semiconductor heterostructures exhibit high second-order nonlinear susceptibilities in metasurfaces. By optimizing the design, the saturation limits in mid-infrared frequency upconversion in nonlinear metasurfaces are significantly extended. This has important implications for night-vision imaging and compact nonlinear wave mixing systems.
ADVANCED MATERIALS
(2023)
Article
Multidisciplinary Sciences
Jiaxin Li, Ying Li, Pei-Chao Cao, Minghong Qi, Xu Zheng, Yu-Gui Peng, Baowen Li, Xue-Feng Zhu, Andrea Alu, Hongsheng Chen, Cheng-Wei Qiu
Summary: The reciprocity principle governs the symmetry in transmission of electromagnetic and acoustic waves, as well as the diffusion of heat. Recent interest in materials with time-modulated properties has shown efficient breaking of reciprocity for various forms of diffusion. However, time modulation may not be a viable approach to break thermal reciprocity. Our theoretical framework and experimental demonstration highlight the generally preserved nature of thermal reciprocity in dynamic materials.
NATURE COMMUNICATIONS
(2022)
Editorial Material
Materials Science, Multidisciplinary
Andrea Alu
Summary: In this article, Andrea Alu, the incoming Editor-in-Chief of Optical Materials Express, shares his vision for the journal.
OPTICAL MATERIALS EXPRESS
(2022)
Article
Multidisciplinary Sciences
Xiaoqian Shu, Aodong Li, Guangwei Hu, Jian Wang, Andrea Alu, Lin Chen
Summary: The authors propose a highly efficient and compact chiral mode converter based on encircling exceptional points, enabling chiral mode switching with high transmission efficiency. The proposed scheme offers a promising approach for high-efficiency and highly integrated chiral mode switching in various practical applications.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Qing Zhang, Qingdong Ou, Guangyuan Si, Guangwei Hu, Shaohua Dong, Yang Chen, Jincheng Ni, Chen Zhao, Michael S. Fuhrer, Yuanjie Yang, Andrea Alu, Rainer Hillenbrand, Cheng-Wei Qiu
Summary: Recent research has shown that highly asymmetric and unidirectional phonon polaritons can be excited by directly patterning high-symmetry crystal structures. Structural engineering in high-symmetry vdW materials allows versatile and robust control over the propagation of phonon polaritons, opening up new possibilities for controlling infrared polaritons.
Article
Chemistry, Multidisciplinary
Julian Klein, Zhigang Song, Benjamin Pingault, Florian Dirnberger, Hang Chi, Jonathan B. Curtis, Rami Dana, Rezlind Bushati, Jiamin Quan, Lukas Dekanovsky, Zdenek Sofer, Andrea Alu, Vinod M. Menon, Jagadeesh S. Moodera, Marko Loncar, Prineha Narang, Frances M. Ross
Summary: Atomic-level defects in van der Waals (vdW) materials are essential for quantum technologies and sensing applications. The magnetic semiconductor CrSBr, with a direct gap and rich magnetic phase diagram, exhibits optically active defects that are correlated with the magnetic environment. The narrow defect emission in CrSBr is related to both the bulk magnetic order and an additional defect-induced magnetic order. This study establishes vdW magnets like CrSBr as an exceptional platform for studying defects and creating tailor-made magnetic textures with optical access.
Article
Nanoscience & Nanotechnology
Guangwei Hu, Weiliang Ma, Debo Hu, Jing Wu, Chunqi Zheng, Kaipeng Liu, Xudong Zhang, Xiang Ni, Jianing Chen, Xinliang Zhang, Qing Dai, Joshua D. Caldwell, Alexander Paarmann, Andrea Alu, Peining Li, Cheng-Wei Qiu
Summary: Various optical crystals with opposite permittivity components have been observed and characterized in the mid-infrared regime. These crystals possess hyperbolic polaritons with large-momenta optical modes and wave confinement, making them promising for nanophotonic on-chip technologies. Monoclinic CdWO4 crystals are shown to exhibit symmetry-broken hyperbolic phonon polaritons and offer new opportunities for polaritonic phenomena.
NATURE NANOTECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Andrea Cordaro, Brian Edwards, Vahid Nikkhah, Andrea Alu, Nader Engheta, Albert Polman
Summary: As traditional microelectronic technology reaches its limits in speed and power consumption, there is a strong demand for novel computing strategies. Analogue optical computing has the advantage of processing large amounts of data at high speeds with negligible energy costs. Researchers have recently explored ultrathin optical metasurfaces for real-time image processing, particularly for edge detection. By incorporating feedback, they have also demonstrated that metamaterials can be used to solve complex mathematical problems, although this has been limited to guided-wave systems and large setups. This study presents an ultrathin Si metasurface-based platform for analogue computing, capable of solving Fredholm integral equations of the second kind using free-space visible radiation. The device combines an inverse-designed Si-based metagrating with a semitransparent mirror to perform the required Neumann series and solve the equation in the analogue domain at the speed of light. The use of visible wavelength operation enables a compact, ultrathin device that can be integrated on a chip and has high processing speeds.
NATURE NANOTECHNOLOGY
(2023)
Editorial Material
Materials Science, Multidisciplinary
Andrea Alu
Summary: Optical Materials Express Editor-in-Chief, Andrea Ali, has introduced new topic categories for the Journal, redefining the Journal scope and better reflecting the current state of this dynamic field of research.
OPTICAL MATERIALS EXPRESS
(2023)
Article
Nanoscience & Nanotechnology
Sander A. . Mann, Heedong Goh, Andrea Alu
Summary: Enabling strong nonlinear optical phenomena requires carefully designed photonic devices to maximize light-matter interactions. Topology optimization has been widely used in optimizing photonic devices due to its efficiency in dealing with large parameter spaces. However, the application of topology optimization in nonlinear effects in dielectric structures is limited.
Article
Nanoscience & Nanotechnology
Nikita Nefedkin, Michele Cotrufo, Andrea Alu
Summary: Nonreciprocity originating from classical interactions among nonlinear scatterers is explored in this work, offering a promising tool for quantum information processing and quantum computing. It is shown that large nonreciprocal responses can be achieved in nonlinear systems by controlling the position and transition frequencies of the atoms, without requiring a nonreciprocal environment. The connection between this effect and the asymmetric population of a slowly decaying dark state is demonstrated.
Article
Polymer Science
M. G. Garzon Altamirano, M. G. Abebe, J. Lejeune, A. Cayla, B. Maes, J. Odent, J. M. Raquez, C. Campagne, E. Devaux
Summary: Efficient thermal management is crucial for maintaining energy balance and thermal comfort. The design of textiles that can regulate the infrared radiation emitted by the human body is appealing. By coating commercial woven fabrics with poly(N-isopropylacrylamide) hydrogels embedded with submicron-sized silica particles, the reflection of infrared radiation can be increased from 12% to 24% in the 5-15 μm wavelengths range. Further management of the silica particles allows reaching a reflection capacity of 36%. This research opens opportunities for energy-saving heating solutions in enclosed spaces.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Optics
S. Smeets, B. Maes, G. Rosolen
Summary: This research presents a general framework for computing the two-photon spontaneous emission rate of a quantum emitter near a photonic structure beyond the dipolar approximation. The framework analytically calculates the emitter contribution while determining the influence of the photonic environment using Purcell factors obtained from electromagnetic simulations. The study demonstrates a significant enhancement in the two-photon transition rate near a silver nanodisk with a hydrogen-like emitter.
Article
Materials Science, Multidisciplinary
Luca Stefanini, Shixiong Yin, Davide Ramaccia, Andrea Alu, Alessandro Toscano, Filiberto Bilotti
Summary: This paper investigates the possibility of realizing temporal metamaterials without changing the material properties, but by varying the boundaries to manipulate the effective refractive index and wave impedance perceived by the wave during propagation. The concept of suddenly changing the structural dispersion of a waveguide through varying boundary conditions is demonstrated to induce an effective temporal interface. This approach can also be extended to temporally controlled metasurfaces, enabling easier design and realization of novel devices based on time-varying metamaterials at microwave and optical frequencies.
Article
Optics
Shixiong Yin, Yao-Ting Wang, Andrea Alu
Summary: This work investigates wave scattering at time-interfaces involving chiral media and demonstrates the effect of temporal optical activity. The study shows that a propagating wave can be split into two orthogonal circular polarization waves oscillating at different frequencies upon a chiral time-interface. The analysis also considers the effect of material dispersion and highlights opportunities for the emergence of multiple scattered waves from the time-interface and interference.
