- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Large-Scale Growth of Ultrathin Low-Dimensional Perovskite Nanosheets for High-Detectivity Photodetectors
摘要： Low-dimensional organic-inorganic hybrid perovskites have demonstrated to be promising semiconductor materials due to their unique optoelectronic properties, however, the controllable growth of high-quality ultrathin 2D perovskites with large lateral dimension still faces great challenges. Herein, we report the controllable growth of large-scale ultrathin 2D (C6H5(CH2)3NH3)3Pb2I7 ((PPA)3Pb2I7) perovskite nanosheets (NSs) using a facile antisolvent-assisted crystallization approach under mild condition. As a result, the well-defined regular-shaped (PPA)3Pb2I7 NSs, with the largest lateral size over 100 micrometers, have been successfully synthesized, which is more than several ten times larger than that of other 2D perovskites NSs previously reported. Moreover, the thickness of the achieved 2D perovskite NSs can be well-tuned by altering the concentration of the precursor solution, with the smallest thickness down to ~4.7 nm. More importantly, the photodetectors based on the high-quality (PPA)3Pb2I7 perovskites exhibit fascinating performance, including an extremely low dark current (~1.5 pA), fast response/recovery rate (~850/780 μs) and high detectivity (~1.2×1010 Jones). This work provides a simple and promising strategy to controllably grow large-scale and ultrathin 2D perovskite NSs for low-cost and high-performance optoelectronic devices.
关键词： low-dimensional perovskite,antisolvent-assisted crystallization approach,large size,photodetectors,ultrathin,nanosheets
更新于2025-09-12 10:27:22
-
Multifunctional semitransparent organic solar cells with excellent infrared photon rejection
摘要： Semitransparent organic solar cells (ST-OSCs) have the potentials to open promising applications that differ from those of conventional inorganic ones, such as see-through power windows with both energy generation and heat insulation functions. However, to achieve so, there remain significant challenges, especially for balancing critical parameters, such as power conversion efficiency (PCE), average visible transparency (AVT) and low energy infrared photon radiation rejection (IRR) to realize the full potentials of ST-OSCs. Herein, we demonstrate the new design of ST-OSCs through the rational integration of organic materials, transparent electrode and infrared photon reflector in one device. With the assistance of optical simulation, new ST-OSCs with precise layout exhibit state-of-art performance, with near 30% AVT and PCE of 7.3%, as well as an excellent IRR of over 93% (780–2500 nm), representing one of best multifunctional ST-OSCs with promising perspective for window application.
关键词： Distributed Bragg reflector,Semitransparent organic solar cell,Ultrathin silver,Average visible transparency,Infrared radiation rejection
更新于2025-09-12 10:27:22
-
Production and photovoltaic characterisation of n-Si/p-CZTS heterojunction solar cells based on a CZTS ultrathin active layers
摘要： In this study, Au/n-Si/p-CZTS/Ag solar cells have been produced by using PLD technique. Ultrathin CZTS films have been grown on n-Si wafer in different thicknesses depending on number of laser pulses. These ultrathin CZTS films were analysed by XRD, AFM and UV-vis spectra. J-V characteristics of Au/n-Si/p-CZTS/Ag solar cells have been determined based on thickness of ultrathin CZTS films under AM 1.5 solar radiation of 80 mW/cm2. Short circuit current density (mA/cm2), fill factor, open circuit voltage (V) and power conversion efficiency (%) of ultrathin CZTS film solar cells have been determined for device produced in this work. The photovoltaic (PV) characteristics of ultrathin CZTS film solar cells has been discussed in detail in this present article and, as a result, the ideal ultrathin CZTS film solar cell structure having the highest efficiency has been determined and concluded.
关键词： efficiency,ultrathin films,Solar cell,PLD,CZTS,Si
更新于2025-09-11 14:15:04
-
Reflective Back Contacts for Ultrathin Cu(In,Ga)Se2-Based Solar Cells
摘要： We report on the development of highly reflective back contacts (RBCs) made of multilayer stacks for ultrathin CIGS solar cells. Two architectures are compared: they are made of a silver mirror coated either with a single layer of In2O3:Sn (ITO) or with a bilayer of ZnO:Al/ITO. Due to the improvement of CIGS rear reflectance, both back contacts result in a significant external quantum efficiency enhancement, in agreement with optical simulations. However, solar cells fabricated with Ag/ITO back contacts exhibit a strong shunting behavior. The key role of the ZnO:Al layer to control the morphology of the top ITO layer and to avoid silver diffusion through the back contact is highlighted. For a 500-nm-thick CIGS layer, this optimized RBC leads to a best cell with a short-circuit current of 27.8 mA/cm2 (+2.2 mA/cm2 as compared to a Mo back contact) and a 12.2%-efficiency (+2.5% absolute).
关键词： photovoltaic cells,reflective back contacts,ultrathin Cu(In,Ga)Se2,In2O3:Sn
更新于2025-09-11 14:15:04
-
Engineering CIGS grains qualities to achieve high efficiency in ultrathin Cu(In Ga1?)Se2 solar cells with a single-gradient band gap profile
摘要： Reducing the Cu(InxGa1?x)Se2 (CIGS) thickness is an effective way to reduce the material use and increase manufacturing throughput. However, it is still a challenge to obtain high efficiency in the ultrathin CIGS solar cell. Here, the CIGS solar cell with a 1.3 μm-thickness-CIGS was synthesized via a three-stage co-evaporation method. The obtained CIGS solar cells were characterized by capacitance-voltage, capacitance-frequency, secondary ion mass spectrometry, X-ray fluorescence, transmission electron microscope, and electron beam induced current techniques. By optimizing the grain size, interface quality, and the Ga gradient in the ultrathin CIGS solar cell, the highest efficiency reached to 11.72% without any light trapping and anti-reflecting coating techniques. Compared with the typical CIGS solar cell with a thickness of 2.3 μm, the ultrathin CIGS solar cell showed a higher open-circuit voltage due to formation a back electrical field. The grain boundaries were found to be beneficial to the carrier’s separation and transport. The ultrathin CIGS solar cell had good ability to resist ion bombardment, suggesting its potential application in the space devices. Our results provide a strategy to achieve high-efficiency ultrathin CIGS solar cells.
关键词： High interface quality,Cu(InxGa1?x)Se2 solar cells,Heavy ion bombardment,Ultrathin
更新于2025-09-11 14:15:04
-
The role of NaF post-deposition treatment on the photovoltaic characteristics of semitransparent ultrathin Cu(In,Ga)Se <sub/>2</sub> solar cells prepared on indium-tin-oxide back contacts: a comparative study
摘要： Cu(In,Ga)Se2 (CIGSe) solar cells with absorber thicknesses of <500 nm are important for lowering the cost of photovoltaic (PV)-generated electricity. Moreover, ultrathin bifacial CIGSe solar cells can be prepared on indium-tin-oxide (ITO) back contacts (BCs). In contrast to Mo BCs, ITO BCs suppress the di?usion of Na from soda-lime glass (SLG) to the CIGSe absorber. Na present in the absorber is supposed to ameliorate the PV properties of CIGSe solar cells, but in the absence of Na or when the Na concentration is extremely low, the PV performance is expected to be poor. In this study, a NaF post-deposition treatment (PDT) was applied to a <500 nm thick semitrasparent CIGS absorber prepared by a 1-stage co-evaporation process. A detailed comparison is made between the CIGSe solar cell that underwent the NaF PDT (C–Na) and a reference CIGSe solar cell in which no Na was supplied from an external source (C0). All the PV parameters (i.e., the open-circuit voltage, short-circuit current density, ?ll factor, and e?ciency) of C–Na considerably improved compared with those of C0. To understand the factors that led to this improvement, the solar cells are analyzed by various characterization techniques, including JV measurements, external quantum e?ciency measurements, temperature-dependent measurements of the open-circuit voltage, capacitance–voltage measurements, drive level capacitance pro?lometry, and admittance spectroscopy. Furthermore, the reaction occurring at the CIGSe/ITO interface is investigated with transmission electron microscopy, and the implications of this reaction on the device performance are discussed.
关键词： ultrathin,solar cells,semitransparent,indium-tin-oxide back contacts,NaF post-deposition treatment,Cu(In,Ga)Se2,photovoltaic characteristics
更新于2025-09-11 14:15:04
-
Synthesis and improved photoluminescence of hexagonal crystals of Li <sub/>2</sub> ZrF <sub/>6</sub> :Mn <sup>4+</sup> for warm WLED application
摘要： Engineering compositions, structures, and defects can endow nanomaterials with optimized catalytic properties. Here, we report that cobalt oxide (CoOx) ultrathin nanosheets (UTNS, ～1.6 nm thick) with a large number of oxygen defects and mixed cobalt valences can be obtained through a facile one-step hydrothermal protocol. The large number of oxygen defects make the ultrathin CoOx nanosheet a superior OER catalyst with low overpotentials of 315 and 365 mV at current densities of 50 and 200 mA cm?2, respectively. The stable framework-like architectures of the UTNS further ensure their high OER activity and durability. Our method represents a facile one-step preparation of CoOx nanostructures with tunable compositions, morphologies, and defects, and thus promotes OER properties. This strategy may find its wider applicability in designing active, robust, and easy-to-obtain catalysts for OER and other electrocatalytic systems.
关键词： ultrathin nanosheets,oxygen evolution reaction,electrocatalysis,hydrothermal synthesis,cobalt oxide
更新于2025-09-11 14:15:04
-
Efficient blue phosphorescent organic light emitting diodes based on exciplex and ultrathin Firpic sandwiched layer
摘要： The high efficient blue phosphorescent organic light emitting diodes (PHOLEDs) employing ultrathin Firpic layer sandwiched between electron donor mCP and electron acceptor TmPyPB layers were fabricated, and the dependence of the electroluminescence (EL) performance on the ultrathin Firpic layer thickness were investigated. It was found that the Firpic layer thickness imposed vital influence on the OLEDs EL efficiency and the one with the 0.3nm Firpic demonstrated the optimal power efficiency (PE) of 50 lm/w and the external quantum efficiency (EQE) close to 18%. The sandwiched ultrathin Firpic layer would not impede the formation of the exciplex between mCP and TmPyPB, and the balance between the exciplex formation and exciplex decaying showed strong dependence on Firpic layer thickness and imposed vital influence on the energy transfer, fluorescence and phosphorescence inside the emissive layer. There were three radiative decaying processes involved, i.e. the prompt and delayed fluorescence (PF and DF) of the exciplex as well as the phosphorescence (PH) of the Firpic, and the final EL relied on the competition of those processes. The optimal EL performance might be attributed to the combining benefits of the balanced PF, DF and PH decaying, alleviated Dexter-transfer-based triplet-triplet annihilation (TTA) and the triplets diffusion suppressed architecture.
关键词： ultrathin,energy transfer,exciplex,TTA
更新于2025-09-10 09:29:36
-
Enhancement of photoluminescence efficiency in GeSe ultrathin slab by thermal treatment and annealing: experiment and first-principles molecular dynamics simulations
摘要： The effect of thermal treatment and annealing under different temperatures from 100 °C to 250 °C on the photoluminescence spectroscopy of the GeSe ultrathin slab is reported. After the thermal treatment and annealing under 200 °C, we found that the photoluminescence intensity of A exciton and B exciton in GeSe ultrathin slab is increased to twice as much as that in untreated case, while is increased by ~84% in the photoluminescence intensity of C exciton. Combined by our experimental work and theoretical simulations, our study confirms the significant role of thermal treatments and annealing in reducing surface roughness and removing the Se vacancy to form more compact and smoother regions in GeSe ultrathin slab. Our findings imply that the improved quality of GeSe surface after thermal treatments is an important factor for the photoluminescence enhancement.
关键词： annealing,ultrathin slab,first-principles molecular dynamics,GeSe,photoluminescence,thermal treatment
更新于2025-09-10 09:29:36
-
On-Demand CMOS-Compatible Fabrication of Ultrathin Self-Aligned SiC Nanowire Arrays
摘要： The field of semiconductor nanowires (NWs) has become one of the most active and mature research areas. However, progress in this field has been limited, due to the difficulty in controlling the density, orientation, and placement of the individual NWs, parameters important for mass producing nanodevices. The work presented herein describes a novel nanosynthesis strategy for ultrathin self-aligned silicon carbide (SiC) NW arrays (≤ 20 nm width, 130 nm height and 200–600 nm variable periodicity), with high quality (~2 ? surface roughness, ~2.4 eV optical bandgap) and reproducibility at predetermined locations, using fabrication protocols compatible with silicon microelectronics. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopic ellipsometry, atomic force microscopy, X-ray diffractometry, and transmission electron microscopy studies show nanosynthesis of high-quality polycrystalline cubic 3C-SiC materials (average 5 nm grain size) with tailored properties. An extension of the nanofabrication process is presented for integrating technologically important erbium ions as emission centers at telecom C-band wavelengths. This integration allows for deterministic positioning of the ions and engineering of the ions’ spontaneous emission properties through the resulting NW-based photonic structures, both of which are critical to practical device fabrication for quantum information applications. This holistic approach can enable the development of new scalable SiC nanostructured materials for use in a plethora of emerging applications, such as NW-based sensing, single-photon sources, quantum LEDs, and quantum photonics.
关键词： silicon carbide,telecom wavelengths,nanofabrication,self-aligned nanowires,ultrathin nanowires,quantum photonics
更新于2025-09-10 09:29:36