Journals > > Topics > Materials
Materials|328 Article(s)
Regulation of SnO2 Electron Transport Layers for Perovskite Solar Cells
Yupeng Cui, Jue Gong, and Mingzhen Liu
Being an important part of planar heterojunction perovskite solar cells (PSCs), electron transport layer (ETL) plays important roles in enhancing the photovoltaic performance and stability of PSCs. Despite the two most commonly used ETL materials, titanium dioxide (TiO2) and tin oxide (SnO2) all being nanoparticles and fabricated through solution method, TiO2 suffers from low electron mobility, large device hysteresis, weak chemical stability and high-temperature processing. By comparison, SnO2 owns the advantages of excellent optoelectronic properties, greater stability because of its chemical inertness and low-temperature processability. We focus on the stability and interfacial charge extraction in PSCs based on SnO2 ETL. First, physical properties and advantages of SnO2 are reviewed. Then, starting from the preparation and film formation methods of SnO2 (e.g. chemical bath deposition, solution spin-coating, etc.), we further discuss the bulk and surface defects of SnO2. Finally, targeting the defect profiles of SnO2 ETL, we emphasize regulatory approaches to enhance the device stability and carrier extraction in PSCs based on interfacial passivation, bulk doping and double-ETL structures. This review article contributes to the further advancements of device performance and stability of PSCs, and provides insights for the practical application of this emerging photovoltaic technology. Being an important part of planar heterojunction perovskite solar cells (PSCs), electron transport layer (ETL) plays important roles in enhancing the photovoltaic performance and stability of PSCs. Despite the two most commonly used ETL materials, titanium dioxide (TiO2) and tin oxide (SnO2) all being nanoparticles and fabricated through solution method, TiO2 suffers from low electron mobility, large device hysteresis, weak chemical stability and high-temperature processing. By comparison, SnO2 owns the advantages of excellent optoelectronic properties, greater stability because of its chemical inertness and low-temperature processability. We focus on the stability and interfacial charge extraction in PSCs based on SnO2 ETL. First, physical properties and advantages of SnO2 are reviewed. Then, starting from the preparation and film formation methods of SnO2 (e.g. chemical bath deposition, solution spin-coating, etc.), we further discuss the bulk and surface defects of SnO2. Finally, targeting the defect profiles of SnO2 ETL, we emphasize regulatory approaches to enhance the device stability and carrier extraction in PSCs based on interfacial passivation, bulk doping and double-ETL structures. This review article contributes to the further advancements of device performance and stability of PSCs, and provides insights for the practical application of this emerging photovoltaic technology.
Laser & Optoelectronics Progress
- Publication Date: Mar. 10, 2024
- Vol. 61, Issue 5, 0516002 (2024)
Low-Dimensional Perovskite Templated Growth of MAPbI3 Perovskite Crystals and Photovoltaic Performance of Solar Cells
Yunyun Yang, Jingyi Wu, Yinyi Ma, Jue Gong, and Faming Li
Due to low costs and exceptional photoelectric properties, perovskite solar cell materials have attracted great attention. During the fabrication of perovskite light-absorbing layers, dual-source vapor-deposited perovskite thin films suffer from long-standing issues of unknown growth mechanism and inferior crystallization quality, which negatively impacts the optical absorbance and charge carrier lifetimes of perovskite thin films, impeding the performance development of vapor-deposited perovskite solar cell devices. By utilizing bulky organic cations with different radii, this work designs quasi two-dimensional perovskite materials, and apply them as buffering templates at the perovskite/hole transport layer interfaces, thus manipulating the crystal growth process of vapor-deposited perovskite grains. The modified crystallization patterns result in vertically grown perovskite grains with columnar shapes, which notably enhances light-absorbing properties and carrier lifetimes of perovskite layers, boosting the power conversion efficiency from 16.21% to 19.55% on perovskite solar cells. The abovementioned results have provided valuable references to the vapor-deposited perovskite films and photovoltaic devices with outstanding optoelectronic performance. Due to low costs and exceptional photoelectric properties, perovskite solar cell materials have attracted great attention. During the fabrication of perovskite light-absorbing layers, dual-source vapor-deposited perovskite thin films suffer from long-standing issues of unknown growth mechanism and inferior crystallization quality, which negatively impacts the optical absorbance and charge carrier lifetimes of perovskite thin films, impeding the performance development of vapor-deposited perovskite solar cell devices. By utilizing bulky organic cations with different radii, this work designs quasi two-dimensional perovskite materials, and apply them as buffering templates at the perovskite/hole transport layer interfaces, thus manipulating the crystal growth process of vapor-deposited perovskite grains. The modified crystallization patterns result in vertically grown perovskite grains with columnar shapes, which notably enhances light-absorbing properties and carrier lifetimes of perovskite layers, boosting the power conversion efficiency from 16.21% to 19.55% on perovskite solar cells. The abovementioned results have provided valuable references to the vapor-deposited perovskite films and photovoltaic devices with outstanding optoelectronic performance.
Laser & Optoelectronics Progress
- Publication Date: Mar. 10, 2024
- Vol. 61, Issue 5, 0516001 (2024)
Research Progress on Excitonic Upconversion Photoluminescence in Two-Dimensional Materials (Invited)
Haiyi Liu, and Pengfei Qi
Upconversion photoluminescence, an anti-Stokes process in which the emitted photon energy exceeds the excitation photon energy, can effectively achieve energy renormalization and conversion, with great application prospects in fields such as biological imaging, solar cells, photocatalysis, and optical refrigeration. As a strategically important new material in the post-Moore era, two-dimensional materials are crucial in realizing efficient room-temperature excitonic upconversion because of their large dipole moments, narrow linewidths, low disorder, and high exciton binding energies, which have recently attracted extensive research interest. This study first introduces the luminescence mechanisms used to achieve photon upconversion, including phonon-assisted upconversion, two-photon absorption, and Auger recombination. Then, research on upconversion based on two-dimensional material systems, such as hexagonal boron nitride, monolayer transition metal dichalcogenides, and two-dimensional perovskites, is summarized. Modulation and enhancement approaches for upconversion in two-dimensional materials that target low upconversion efficiency are also discussed. Finally, application prospects of excitonic upconversion effects in two-dimensional material systems are envisioned. Upconversion photoluminescence, an anti-Stokes process in which the emitted photon energy exceeds the excitation photon energy, can effectively achieve energy renormalization and conversion, with great application prospects in fields such as biological imaging, solar cells, photocatalysis, and optical refrigeration. As a strategically important new material in the post-Moore era, two-dimensional materials are crucial in realizing efficient room-temperature excitonic upconversion because of their large dipole moments, narrow linewidths, low disorder, and high exciton binding energies, which have recently attracted extensive research interest. This study first introduces the luminescence mechanisms used to achieve photon upconversion, including phonon-assisted upconversion, two-photon absorption, and Auger recombination. Then, research on upconversion based on two-dimensional material systems, such as hexagonal boron nitride, monolayer transition metal dichalcogenides, and two-dimensional perovskites, is summarized. Modulation and enhancement approaches for upconversion in two-dimensional materials that target low upconversion efficiency are also discussed. Finally, application prospects of excitonic upconversion effects in two-dimensional material systems are envisioned.
Laser & Optoelectronics Progress
- Publication Date: Feb. 10, 2024
- Vol. 61, Issue 3, 0316007 (2024)
Phosphate-Bismuthate Glass and Fiber with Heavy Doping of Silver Nanoparticles (Invited)
Fuguang Chen, Bofan Jiang, Zhi Chen, Siyuan Ma, Yupeng Huang, Hang Zhang, and Zhijun Ma
Glass with heavy doping of noble metal nanoparticles is expected to exhibit high optical nonlinearity. In this study, the effects of glass composition, structure, and heat treatment on the formation of silver nanoparticles (Ag NPs) in phosphate-bismuthate (PB) glass are investigated. By optimizing the chemical composition and preparation parameters, strong localized surface plasmon resonance is achieved in the PB glass with a silver mass fraction of more than 13%, which is 20 and 6 times higher than that in bismuthate and phosphate glasses reported previously, respectively. The high solubility of the phosphate component and the self-reduction effect of the bismuthate component jointly contributed to the stability and high content of Ag NPs in the PB glass. Z-scan measurements show that such heavy doping PB glass has a reverse saturable absorption coefficient of -14×10-12 m·W-1 and a saturable absorption coefficient of 4.94×10-12 m·W-1 at 800 nm. Furthermore, the heavy doping PB glass exhibits excellent thermal stability, making it promising for the fabrication of nonlinear optical fibers. In addition, with a heavily silver-doped PB glass rod as the core and a commercial silicate glass tube as the cladding, a composite glass fiber with high Ag-NP doping is successfully fabricated using a "molten-core" fiber drawing method. Glass with heavy doping of noble metal nanoparticles is expected to exhibit high optical nonlinearity. In this study, the effects of glass composition, structure, and heat treatment on the formation of silver nanoparticles (Ag NPs) in phosphate-bismuthate (PB) glass are investigated. By optimizing the chemical composition and preparation parameters, strong localized surface plasmon resonance is achieved in the PB glass with a silver mass fraction of more than 13%, which is 20 and 6 times higher than that in bismuthate and phosphate glasses reported previously, respectively. The high solubility of the phosphate component and the self-reduction effect of the bismuthate component jointly contributed to the stability and high content of Ag NPs in the PB glass. Z-scan measurements show that such heavy doping PB glass has a reverse saturable absorption coefficient of -14×10-12 m·W-1 and a saturable absorption coefficient of 4.94×10-12 m·W-1 at 800 nm. Furthermore, the heavy doping PB glass exhibits excellent thermal stability, making it promising for the fabrication of nonlinear optical fibers. In addition, with a heavily silver-doped PB glass rod as the core and a commercial silicate glass tube as the cladding, a composite glass fiber with high Ag-NP doping is successfully fabricated using a "molten-core" fiber drawing method.
Laser & Optoelectronics Progress
- Publication Date: Feb. 10, 2024
- Vol. 61, Issue 3, 0316006 (2024)
Research Progress in Lead-Free Metal Halide Scintillator Materials and Imaging Devices (Invited)
Junzhe Lin, Dan Guo, and Tianrui Zhai
High-energy radiation detection and imaging technology has important applications in high-energy physics research, medical imaging, industrial detection, and other fields. Lead-free metal halides have many advantages, such as low toxicity, good stability, high light yield, and large stokes shift; they exhibit excellent potential in indirect X-ray detection. The latest research progress of lead-free metal halide scintillators and imaging devices is reviewed herein. First, the material composition and luminescence mechanism are introduced. The key parameters of scintillator performance are listed. The synthesis methods of single crystal, powder, and nanocrystal are summarized. Some recent novel ideas about improving the resolution of imaging devices are also described. We focus on the new-type scintillator imaging devices, including composite film, ceramic, glass, and structured scintillators. Finally, we have summarized the challenges and potential problems of scintillator imaging detectors and provided some suggestions. High-energy radiation detection and imaging technology has important applications in high-energy physics research, medical imaging, industrial detection, and other fields. Lead-free metal halides have many advantages, such as low toxicity, good stability, high light yield, and large stokes shift; they exhibit excellent potential in indirect X-ray detection. The latest research progress of lead-free metal halide scintillators and imaging devices is reviewed herein. First, the material composition and luminescence mechanism are introduced. The key parameters of scintillator performance are listed. The synthesis methods of single crystal, powder, and nanocrystal are summarized. Some recent novel ideas about improving the resolution of imaging devices are also described. We focus on the new-type scintillator imaging devices, including composite film, ceramic, glass, and structured scintillators. Finally, we have summarized the challenges and potential problems of scintillator imaging detectors and provided some suggestions.
Laser & Optoelectronics Progress
- Publication Date: Feb. 10, 2024
- Vol. 61, Issue 3, 0316005 (2024)
Li3Na3Ga2F12∶Cr3+ Fluoride Wideband Near-Infrared Fluorescence Material Synthesized by Green Method (Invited)
Yang Li, Xiang Yu, Ximei An, Qiaoling Tan, Hongjia Liu, Zhenzhang Li, and Shaoan Zhang
The near-infrared light source possesses strong penetration, non-destructive testing capabilities, and a high signal-to-noise ratio for biological tissues. It finds extensive applications in component detection, security monitoring, biomedicine, national defense, and the military industry. However, the lack of highly efficient and portable near-infrared light sources has become a key obstacle to the development of intelligent detection technology. In comparison with traditional near-infrared light sources, phosphor-converted near-infrared LED light sources (NIR pc-LEDs) offer advantages such as portability and high efficiency. This study focuses on synthesizing Li3Na3Ga2F12∶Cr3+ broadband phosphors through a simple and environmentally friendly hydrothermal synthesis method. By controlling factors like holding temperature and holding time, an optimal synthesis scheme for fluorescent materials is determined. The influence of fluoride particle size, morphology evolution, and Cr3+ doping concentration on the luminescence properties of Li3Na3Ga2F12∶Cr3+ is also investigated. The synthesized Li3Na3Ga2F12∶Cr3+ material exhibits broadband emission ranging from 630 nm to 980 nm with a full width at half maximum (FWHM) of 110 nm and a peak value at 766 nm. Its internal quantum efficiency reaches an impressive 74%. Through successful packaging with commercial blue LED, a NIR wideband LED source is achieved. The output power of NIR light at 50 mA driving current is 10.32 mW, and the photoelectric conversion efficiency reaches 5.1%. Finally, the feasibility of using the NIR broadband LED light source in imaging fields such as medical and food detection is verified by NIR imaging of veins under chicken breast and night vision imaging demonstrations. The near-infrared light source possesses strong penetration, non-destructive testing capabilities, and a high signal-to-noise ratio for biological tissues. It finds extensive applications in component detection, security monitoring, biomedicine, national defense, and the military industry. However, the lack of highly efficient and portable near-infrared light sources has become a key obstacle to the development of intelligent detection technology. In comparison with traditional near-infrared light sources, phosphor-converted near-infrared LED light sources (NIR pc-LEDs) offer advantages such as portability and high efficiency. This study focuses on synthesizing Li3Na3Ga2F12∶Cr3+ broadband phosphors through a simple and environmentally friendly hydrothermal synthesis method. By controlling factors like holding temperature and holding time, an optimal synthesis scheme for fluorescent materials is determined. The influence of fluoride particle size, morphology evolution, and Cr3+ doping concentration on the luminescence properties of Li3Na3Ga2F12∶Cr3+ is also investigated. The synthesized Li3Na3Ga2F12∶Cr3+ material exhibits broadband emission ranging from 630 nm to 980 nm with a full width at half maximum (FWHM) of 110 nm and a peak value at 766 nm. Its internal quantum efficiency reaches an impressive 74%. Through successful packaging with commercial blue LED, a NIR wideband LED source is achieved. The output power of NIR light at 50 mA driving current is 10.32 mW, and the photoelectric conversion efficiency reaches 5.1%. Finally, the feasibility of using the NIR broadband LED light source in imaging fields such as medical and food detection is verified by NIR imaging of veins under chicken breast and night vision imaging demonstrations.
Laser & Optoelectronics Progress
- Publication Date: Feb. 10, 2024
- Vol. 61, Issue 3, 0316004 (2024)
Terahertz Sensing with Exceptional Points in Metasurfaces (Invited)
Yuancheng Fan, Zhenning Yang, Ziyi Xu, Hong Zhang, Kangyao Sun, Zhehao Ye, Fuli Zhang, and Jing Lou
Exceptional points are singularities in non-Hermitian systems, generated when two or more eigenvalues and their corresponding eigenvectors merge simultaneously. Metasurfaces are two-dimensional artificial electromagnetic materials constructed at subwavelength scales, which provide a versatile platform for studying this non-Hermitian phenomenon by introducing dissipation and amplification within their unit cells. This paper provides an overview of the latest research progress in exceptional points sensing. It begins by introducing the basic theory of non-Hermitian systems and exceptional points, then focuses on the research achievements in exceptional points sensing on metasurfaces in terahertz band. Lastest, we summarize the disadvantages of exceptional points sensing, and its future development trends are also discussed. Exceptional points are singularities in non-Hermitian systems, generated when two or more eigenvalues and their corresponding eigenvectors merge simultaneously. Metasurfaces are two-dimensional artificial electromagnetic materials constructed at subwavelength scales, which provide a versatile platform for studying this non-Hermitian phenomenon by introducing dissipation and amplification within their unit cells. This paper provides an overview of the latest research progress in exceptional points sensing. It begins by introducing the basic theory of non-Hermitian systems and exceptional points, then focuses on the research achievements in exceptional points sensing on metasurfaces in terahertz band. Lastest, we summarize the disadvantages of exceptional points sensing, and its future development trends are also discussed.
Laser & Optoelectronics Progress
- Publication Date: Feb. 10, 2024
- Vol. 61, Issue 3, 0316003 (2024)
Research Progress of Ultraviolet Nonlinear Optical Crystal K3B6O10Br (Invited)
Min Zhang, Haoran Wang, and Ling Zhang
Using nonlinear optical crystals for laser frequency conversion is a key method for extending laser wavelengths. These crystals, particularly borates, are crucial in all solid-state laser systems, especially for ultraviolet laser output, due to their diverse structures and superior optical properties. The K3B6O10Br crystal, notable for its short ultraviolet cutoff edge (182 nm), significant nonlinear optical coefficient (d22 of 0.83 pm/V), and moderate birefringence index (0.046@1064 nm), shows promise in second and third harmonic laser output. This article provides an overview of the growth and fundamental characteristics of the K3B6O10Br crystal. Recent advancements in visible/ultraviolet lasers and optical parametric chirped pulse amplification, achieved through crystal frequency doubling and sum frequency techniques, are summarized. Additionally, the potential future developments and applications of the K3B6O10Br crystal are explored in this study. Using nonlinear optical crystals for laser frequency conversion is a key method for extending laser wavelengths. These crystals, particularly borates, are crucial in all solid-state laser systems, especially for ultraviolet laser output, due to their diverse structures and superior optical properties. The K3B6O10Br crystal, notable for its short ultraviolet cutoff edge (182 nm), significant nonlinear optical coefficient (d22 of 0.83 pm/V), and moderate birefringence index (0.046@1064 nm), shows promise in second and third harmonic laser output. This article provides an overview of the growth and fundamental characteristics of the K3B6O10Br crystal. Recent advancements in visible/ultraviolet lasers and optical parametric chirped pulse amplification, achieved through crystal frequency doubling and sum frequency techniques, are summarized. Additionally, the potential future developments and applications of the K3B6O10Br crystal are explored in this study.
Laser & Optoelectronics Progress
- Publication Date: Feb. 10, 2024
- Vol. 61, Issue 3, 0316002 (2024)
Photoluminescence of Plasmonic Nanomaterials (Invited)
Xiaofeng Liu, Lin Wang, and Jianrong Qiu
Photoluminescence of plasmon nanomaterials is now a fundamental property of plasmons. Over the past two decades, this phenomenon has been observed in various plasmon materials with diverse structures. This study briefly discusses experimental research progress in plasmon photoluminescence, focusing on the representative types of proposed plasmon photoluminescence and briefly analyzing their photophysical processes. Furthermore, this study explores the cutting-edge applications of photoluminescence using plasmon materials in recent years in sensing, biological imaging, and other fields. Finally, it summarizes the research progress and problems faced in the photoluminescence of plasmon materials, the prospects of this photophysical process, and future research directions. Photoluminescence of plasmon nanomaterials is now a fundamental property of plasmons. Over the past two decades, this phenomenon has been observed in various plasmon materials with diverse structures. This study briefly discusses experimental research progress in plasmon photoluminescence, focusing on the representative types of proposed plasmon photoluminescence and briefly analyzing their photophysical processes. Furthermore, this study explores the cutting-edge applications of photoluminescence using plasmon materials in recent years in sensing, biological imaging, and other fields. Finally, it summarizes the research progress and problems faced in the photoluminescence of plasmon materials, the prospects of this photophysical process, and future research directions.
Laser & Optoelectronics Progress
- Publication Date: Feb. 10, 2024
- Vol. 61, Issue 3, 0316001 (2024)
Photostimulated Information Storage Material for Novel Near-Infrared Writing Based on Thermal-Assisted Excitation (Invited)
Xiaojun Li, Xiaqing Jiang, Caiming Chen, Ruoxi Gao, Zhangwen Long, and Jianbei Qiu
Photostimulated luminescent (PSL) materials written by near-infrared (NIR) light can not only promote the practical application of PSL materials for information storage, but also play a significant role in biological imaging and coding. However, high-capacity PSL materials for NIR writing are still lacking considerably. Herein, BaSi2O5∶Eu2+,Nd3+ with thermal-assisted increment filling capacity that could be excited by ultraviolet light was first selected, and Yb3+ ions were further doped to it for optimizing the thermal conversion of NIR light. Combined with the up-conversion luminescent material NaYF4∶Yb3+,Tm3+ containing blue and violet light emission, intensity multiplexing of optical storage application was successfully demonstrated solely using a 980 nm laser regulation. This study provides an efficient NIR light writing-type PSL material and demonstrates the high efficiency for NIR writing on thermal-assisted photoexcited luminescent materials. Photostimulated luminescent (PSL) materials written by near-infrared (NIR) light can not only promote the practical application of PSL materials for information storage, but also play a significant role in biological imaging and coding. However, high-capacity PSL materials for NIR writing are still lacking considerably. Herein, BaSi2O5∶Eu2+,Nd3+ with thermal-assisted increment filling capacity that could be excited by ultraviolet light was first selected, and Yb3+ ions were further doped to it for optimizing the thermal conversion of NIR light. Combined with the up-conversion luminescent material NaYF4∶Yb3+,Tm3+ containing blue and violet light emission, intensity multiplexing of optical storage application was successfully demonstrated solely using a 980 nm laser regulation. This study provides an efficient NIR light writing-type PSL material and demonstrates the high efficiency for NIR writing on thermal-assisted photoexcited luminescent materials.
Laser & Optoelectronics Progress
- Publication Date: Jan. 10, 2024
- Vol. 61, Issue 1, 0116005 (2024)
Topics
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20