Article
Nanoscience & Nanotechnology
Irati Alonso Calafell, Lee A. Rozema, David Alcaraz Iranzo, Alessandro Trenti, Philipp K. Jenke, Joel D. Cox, Avinash Kumar, Hlib Bieliaiev, Sebastien Nanot, Cheng Peng, Dmitri K. Efetov, Jin-Yong Hong, Jing Kong, Dirk R. Englund, F. Javier Garcia de Abajo, Frank H. L. Koppens, Philip Walther
Summary: Graphene-insulator-metal heterostructures exhibit significantly enhanced optical nonlinearity, offering potential for optically controlled and electrically tunable nano-optoelectronic devices.
NATURE NANOTECHNOLOGY
(2021)
Article
Optics
Phoebe M. Pearce, Eduardo Camarillo Abad, Louise C. Hirst
Summary: Integration of a rear surface nanophotonic grating can enhance the photocurrent in ultra-thin solar cells. Transparent gratings made of dielectric materials and high bandgap semiconductors offer efficient diffraction and lower parasitic absorption. The maximum photocurrent in these gratings depends on the optical constants of the materials used, regardless of the grating dimensions. However, optimization of the grating dimensions is still necessary to maximize the photocurrent for a given active layer thickness.
Article
Optics
Ke Chen, Sheng Wu, Yingchun Yu, Nianhong Zheng, Rui Wu, Hongmei Zheng
Summary: A dual-interface period-mismatched rotating rectangular grating structure was designed for crystalline silicon thin film solar cells, showing improved light-trapping performance through optoelectronic simulation analysis. The research results indicate that the light-trapping effect of the rear grating rotating structure is better than that of the front grating rotating structure.
Article
Chemistry, Physical
Marwa M. Tharwat, Ashwag Almalki, Amr M. Mahros
Summary: This study introduces a randomly distributed plasmonic aluminum nanoparticle array on conventional GaAs thin-film solar cells to enhance sunlight harvesting, analyzing the performance through modifications in absorbance and planar density of the plasmonic layer. The findings suggest that increasing the planar density enhances absorption in the visible region but worsens absorption in the near-infrared region.
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
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
Asghar Fanni Asl, Hamid Heidarzadeh, Hamid Bahador
Summary: This study evaluated the influence of dimensional parameters of trench metal grating on the absorption efficiency of organic solar cells (OSCs) and calculated the plasmonic modes. The width of the grating platform significantly affected the intensity of wedge plasmon polaritons (WPPs) and Gap surface plasmon (GSPs) due to the charge distribution in a plasmonic configuration. Stopped-trench gratings showed better absorption efficiency than thorough-trenched gratings. A stopped-trench gratings model with a coating layer exhibited 77.01% integrated absorption efficiency, outperforming previous works with 19% less photoactive materials.
Review
Materials Science, Multidisciplinary
S. Liu, Y. Sun, L. Chen, Q. Zhang, X. Li, J. Shuai
Summary: Organic solar cells have superior characteristics, but still lag behind inorganic photovoltaics in efficiency. Researchers have successfully improved the photoelectrical properties of OSCs by using various plasmonic nanostructures, which are suitable for enhancing device efficiency.
MATERIALS TODAY PHYSICS
(2022)
Article
Optics
Ke Chen, Nianhong Zheng, Sheng Wu, Jinyang He, Yingchun Yu, Hongmei Zheng
Summary: A dual-layer split nanograting structure is proposed for crystalline silicon thin-film solar cells, showing significantly enhanced light absorption compared to planar structures. Results from optical and electrical simulations demonstrate improved light trapping performance and a 54.6% increase in short-circuit current density.
Article
Nanoscience & Nanotechnology
Desislava Daskalova, Gonzalo Aguila Flores, Ulrich Plachetka, Michael Mo''ller, Julia Wolters, Thomas Wintgens, Max C. Lemme
Summary: We enhance the photocatalytic activity of titanium dioxide (TiO2) by combining nanostructured glass substrates with metallic plasmonic nanostructures. By patterning periodic conical grids on the nanostructured glass, we achieve a three-fold increase in surface area, creating a broadband optical absorber. The addition of aluminum and gold activates the structures plasmonically and increases the optical absorption in TiO2 films, resulting in enhanced photocatalytic activity and effective reduction of water pollutants.
ACS APPLIED NANO MATERIALS
(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
Physics, Applied
Zhefu Liao, Zhengqi Liu, Qizhao Wu, Xuefeng Zhan, Mulin Liu, Guiqiang Liu
Summary: Solar energy has been widely used as a renewable and clean energy source, but the dilemma of choosing between higher absorption but narrowband or broadband but lower absorption when designing solar irradiation absorbers has greatly limited the development of the solar energy industry. A gradient cavity-thin-film metasurface (GCM) made up of alternating multiple layers of titanium and silicon dioxide exhibits ultra-broadband strong absorption in the dominating portion of the solar irradiation spectrum. This impressive near-unity absorption is attributed to multiple light-matter interactions and provides great potential for practical applications in solar thermal energy harvesting and photothermal conversion.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Mina Mirzaei, Javad Hasanzadeh, Ali Abdolahzadeh Ziabari
Summary: The performance of ultrathin CZTS solar cells was significantly improved by incorporating anti-reflective coating and embedding plasmonic nanostructures, resulting in an efficiency increase to 7.45% compared to the reference cell with 5.67% efficiency.
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, Multidisciplinary
Anik Kumar Ghosh, Swagato Sarkar, Takuya Tsuda, Soosang Chae, Andre Knapp, Mirko Nitschke, Amit Das, Sven Wiessner, Tobias A. F. Koenig, Andreas Fery
Summary: Metal-semiconductor nanostructures are widely used in photodetection, photocatalysis, and photovoltaics. In photodetection, the resistance typically decreases with the generation of charge carriers upon illumination, but an opposite response, an increase in resistance, is observed in interconnected metal-semiconductor gratings. This study presents a fabrication method using wrinkle structuring and oblique angle material deposition to create photoresistors with large-area periodic structures and cracks that serve as connections for two-point contact measurements. It is also found that an additional deposition of an amorphous titania layer further enhances the current reduction on photoexcitation.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Review
Nanoscience & Nanotechnology
Sergey G. Menabde, Jacob T. Heiden, Joel D. Cox, N. Asger Mortensen, Min Seok Jang
Summary: Polaritonic modes in low-dimensional materials enable strong light-matter interactions and the manipulation of light on nanometer length scales. The recent interest in image polaritons in van der Waals crystals has gained considerable attention in nanophotonics, where a polaritonic material couples with its mirror image in close proximity to a highly conductive metal. These image modes provide an appealing nanophotonic platform with lower propagation loss and access to the nonlocal regime of light-matter interaction.
Article
Chemistry, Multidisciplinary
Saskia Fiedler, P. Elli Stamatopoulou, Artyom Assadillayev, Christian Wolff, Hiroshi Sugimoto, Minoru Fujii, N. Asger Mortensen, Soren Raza, Christos Tserkezis
Summary: Cathodoluminescence spectroscopy in an electron microscope is a versatile tool for analyzing the optical response of plasmonic and dielectric nanostructures. However, the transition radiation produced by electron impact is often neglected. This study demonstrates that transition radiation can generate distinct resonances that interfere constructively or destructively depending on the electron beam's time-of-flight inside the nanosphere, leading to distorted spectra and potentially erroneous modal assignment.
Article
Optics
Antton Babaze, Eduardo Ogando, P. Elli Stamatopoulou, Christos Tserkezis, N. Asger Mortensen, Javier Aizpurua, Andrei G. Borisov, Ruben Esteban
Summary: In this study, time-dependent density functional theory (TDDFT) was used to investigate the impact of quantum-mechanical effects on the self-interaction Green's function, which governs the electromagnetic interaction between quantum emitters and plasmonic metallic nanoantennas. The results reveal that quantum effects, such as surface-enabled Landau damping and the spill out of induced charges, strongly influence the nanoantenna-emitter interaction, leading to a redshift and broadening of plasmonic resonances. These effects are not considered in classical theories that assume a local dielectric response of the metals.
Article
Multidisciplinary Sciences
Sergejs Boroviks, Zhan-Hong Lin, Vladimir A. Zenin, Mario Ziegler, Andrea Dellith, P. A. D. Goncalves, Christian Wolff, Sergey Bozhevolnyi, Jer-Shing Huang, N. Asger Mortensen
Summary: Nonlocal effects in propagating gap surface plasmon modes in ultrathin metal-dielectric-metal planar waveguides are investigated using scanning near-field optical microscopy. Experimental results show the signatures of nonlocal damping in few-nanometer-sized dielectric gaps.
NATURE COMMUNICATIONS
(2022)
Article
Optics
Fengwen Kang, Yongping Du, Ze Yang, Philippe Boutinaud, Martijn Wubs, Jie Xu, Haiyan Ou, Dongzhe Li, Kaibo Zheng, Abebe T. Tarekegne, Guohuan Sun, Xuhui Xu, Sanshui Xiao
Summary: In this study, CsPbBr3:Ln(3+) nanocrystals grown into glass were successfully designed and fabricated using an in situ nanocrystallization method. It was found that substitution of Pb2+ sites with Ln(3+) ions led to a blueshift of emission position. The nanocrystals exhibited excellent photoluminescent properties and showed good stability in various environments. Additionally, the emission intensity could be controlled through heat-cooling experiments and laser irradiation. Furthermore, a white light-emitting prototype was achieved by combining the CsPbBr3 nanocrystals with other phosphors.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Sergii Morozov, Stefano Vezzoli, Alina Myslovska, Alessio Di Giacomo, N. Asger Mortensen, Iwan Moreels, Riccardo Sapienza
Summary: Giant shell CdSe/CdS quantum dots exhibit high brightness and flexibility, with near-unity quantum yield and suppressed blinking. However, their single photon purity is reduced due to efficient multiexcitonic emission. In this study, we observed a significant blueshift in the photoluminescence biexciton spectrum of pure-phase wurtzite quantum dots. By using spectral filtering, we achieved a 2.3 times reduction in biexciton quantum yield while preserving 60% of the exciton single photon emission, leading to an improvement in purity from g2(0)=0.07±0.01 to g2(0)=0.03±0.01. Furthermore, at higher pump fluence, the spectral purification was even more effective, resulting in up to a 6.6 times reduction in g2(0) by suppressing higher order excitons and shell states with larger blueshifts.
Article
Materials Science, Multidisciplinary
Jie Xu, Yamei Luo, Sanshui Xiao, Fengwen Kang, Kosmas L. Tsakmakidis
Summary: This study proposes an all-optical digital logical system based on unidirectional modes in the microwave regime, which can achieve continuous broadband operation for basic logic gates. Utilizing the concept of negative logic, the system exhibits low-loss, broadband, and robust characteristics, and has the potential for multi-input and/or multi-output logical functionalities, making it promising for parallel computation. The numerical simulations and theoretical analyses support the feasibility of this system.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Rui Chen, Yi Zheng, Xingyu Huang, Qiaoling Lin, Chaochao Ye, Meng Xiong, Martijn Wubs, Yungui Ma, Minhao Pu, Sanshui Xiao
Summary: Obtaining bound states in the continuum (BICs) in photonic crystals allows for resonances with high quality factors for lasing and nonlinear applications. We design photonic-crystal BIC cavities encircled by the photonic bandgap of lateral heterostructures to confine the mode profile and suppress side leakage. Multiple bulk quantized modes are observed in both simulation and experiment, with resonance peaks depending on the illuminating position explained by mode profile distribution analysis and numerical simulations. Our findings have potential applications in mode selectivity for BIC devices and manipulation of lasing modes or radiation patterns in photonic-crystal surface-emitting lasers or nonlinear optics.
BEILSTEIN JOURNAL OF NANOTECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Alvaro Rodriguez Echarri, Fadil Iyikanat, Sergejs Boroviks, N. Asger Mortensen, Joel D. Cox, F. Javier Garcia de Abajo
Summary: The promising applications of photonics rely on the fabrication of high-quality metal thin films with controlled thickness in the range of a few nanometers. These materials exhibit highly nonlinear response to optical fields due to ultrafast electron dynamics. However, the understanding of this phenomenon on such small length scales is limited. In this study, a new mechanism controlling the nonlinear optical response of thin metallic films is revealed, which is dominated by ultrafast electronic heat transport when the film thickness is sufficiently small. By experimentally and theoretically studying electronic transport in these materials, the researchers explained the observed temporal evolution of photoluminescence in two-pulse correlation measurements. They found that ultrafast thermal dynamics plays a crucial role in determining the strength and time-dependent characteristics of the nonlinear photoluminescence signal. Their findings provide new insights into the nonlinear optical response of nanoscale materials and offer possibilities for controlling and utilizing hot carrier distributions in metallic films.
Article
Chemistry, Multidisciplinary
Yuxin Lei, Qiaoling Lin, Sanshui Xiao, Juntao Li, Hanlin Fang
Summary: This work demonstrates the generation of deep defect states in MoTe2 fewlayers via a heating process, enabling light emission in the telecommunication O-band for quantum light emission. Optical measurements reveal localized excitons and strong interaction among defects. Furthermore, the optical emission of defects depends on the thickness of the host materials. These findings offer a new route for tailoring the optical properties of two-dimensional materials in optoelectronic applications.
Article
Materials Science, Multidisciplinary
Saskia Fiedler, Sergii Morozov, Leonid Iliushyn, Sergejs Boroviks, Martin Thomaschewski, Jianfang Wang, Timothy J. Booth, Nicolas Stenger, Christian Wolff, N. Asger Mortensen
Summary: Cathodoluminescence spectroscopy combined with second-order auto-correlation measurements of g(2)(tau) allows for extensive study of the synchronization of photon emitters in low-dimensional structures. Co-existing excitons in two-dimensional transition metal dichalcogenide monolayers serve as a great source of identical photon emitters that can be simultaneously excited by an electron. In this study, we demonstrate large photon bunching with g(2)(0) up to 156 +/- 16 in a tungsten disulfide monolayer (WS2), showing a strong dependence on the electron-beam current. By carefully selecting a simple and compact geometry, such as a thin monocrystalline gold nanodisk, we achieve a record-high bunching g(2)(0) of up to 2152 +/- 236, improving the excitation synchronization and electron-emitter interaction. This approach of controlling electron excitation of excitons in a WS2 monolayer enables the synchronization of photon emitters in an ensemble, which is crucial for advancing light information and computing technologies.
Article
Chemistry, Multidisciplinary
Moritz Fischer, Ali Sajid, Jake Iles-Smith, Alexander Hoetger, Denys I. Miakota, Mark K. Svendsen, Christoph Kastl, Stela Canulescu, Sanshui Xiao, Martijn Wubs, Kristian S. Thygesen, Alexander W. Holleitner, Nicolas Stenger
Summary: By combining theory and experiments, we have identified three carbon-based defects as the microscopic origin of luminescent centers in hBN. We have also developed a method to calculate photoluminescence excitation (PLE) maps, which accurately describe the vibronic structure of the optical transition and the phonon-assisted excitation mechanism.
Article
Nanoscience & Nanotechnology
Saskia Fiedler, Sergii Morozov, Danylo Komisar, Evgeny A. A. Ekimov, Liudmila F. F. Kulikova, Valery A. A. Davydov, Viatcheslav N. N. Agafonov, Shailesh Kumar, Christian Wolff, Sergey I. I. Bozhevolnyi, N. Asger Mortensen
Summary: Impurity-vacancy centers in diamond provide a class of robust photon sources with versatile quantum properties. The ensembles of color centers have tunable photon-emission statistics and their emission properties can be controlled by different types of excitation. Electron-beam excitation can synchronize the emitters' excitation and control the second-order correlation function g(2)(0), as confirmed by experimental results in this letter. Such a photon source based on an ensemble of few color centers in a diamond crystal offers a highly tunable platform for room temperature informational technologies.
Article
Optics
Christos Tserkezis, Christian Wolff, Fedor A. Shuklin, Francesco Todisco, Mikkel H. Eriksen, P. A. D. Goncalves, N. Asger Mortensen
Summary: We propose an efficient approach for actively controlling the Rabi oscillations in nanophotonic emitter-cavity analogs based on the presence of an element with optical gain. Inspired by recent developments in parity-time (PT)-symmetry photonics, we show that nano-or microcavities where intrinsic losses are partially or fully compensated by an externally controllable amount of gain offer unique capabilities for manipulating the dynamics of extended (collective) excitonic emitter systems. Furthermore, we show that there is a specific gain value that leads to an exceptional point, where both the emitter and cavity occupation oscillate practically in phase, with occupation numbers that can significantly exceed unity.
Article
Materials Science, Multidisciplinary
Gino Wegner, Dan-Nha Huynh, N. Asger Mortensen, Francesco Intravaia, Kurt Busch
Summary: The paper discusses the impact of an extended model proposed by Halevi on the nonlocal response of plasmonic materials and nanostructures. It reevaluates the Mie scattering coefficients for a cylinder and corresponding plasmon-polariton resonances within this framework. The analysis reveals a nonlocal, collisional, and size-dependent damping term that affects the resonances in the extinction spectrum. The implementation of the Halevi model in the time domain is particularly important for efficient and accurate modeling of nanogap structures and other nanoscale features in nanoplasmonics applications.
