- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Air exposure oxidation and photooxidation of solution-phase treated PbS quantum dot thin films and solar cells
摘要： The air exposure oxidation mechanisms of PbS quantum dot (QD) thin films and solar cells are studied in the current paper. As a novel and advantageous method, QD thin films were prepared by the single-step deposition of colloidal QDs treated with different ligands of butylamine (BA), mercaptopropionic acid (MPA), tetra-butylammonium iodide (TBAI), methylammonium iodide (MAI) and methylammonium lead triiodide (MAPbI3, perovskite). Photoluminescence (PL) measurements evaluated the stability of different surface treated PbS QDs during the colloidal to thin film transformation, and over the air exposure times. Blue-shift and quenching the PL spectra suggested rapid oxidation of QD thin films at the first times of air exposure. However, the oxidation rates significantly reduced for the QD thin films treated with organic MPA and all the inorganic ligands. According to the X-ray photoelectron spectroscopy (XPS) studies, thin films oxidation accompanied with the formation of PbSO3 and PbSO4 compounds on the (100) facets of PbS QDs. Although MAPbI3 treatment led to the complete passivation of QDs in the air, perovskite shelling partially oxidized to PbO and PbCO3 compounds. Furthermore, the PL enhancement phenomenon observed at the first times of air exposure for the TBAI and MAPbI3-treated QD thin films, as a result of their strong surface passivation as well as the photoenhancement and photoelectrification mechanisms. Eventually, p-n and p-i-n structured solar cells were fabricated by the single-step deposition of solution-phase treated PbS QD inks. In this case, inorganic surface treatments not only increased the power conversion efficiency (PCE) of solar cells, but also led to a high stability of fabricated devices in the air environment (lower than 1% PCE loss after 500 h of storage in the air).
关键词： PbS quantum dot,Solar cell,Ligand,Photooxidation,Thin film,Air stability
更新于2025-09-19 17:13:59
-
Recent Research Progress in Surface Ligand Exchange of PbS Quantum Dots for Solar Cell Application
摘要： Colloidal quantum dots (CQDs) are considered as next-generation semiconductors owing to their tunable optical and electrical properties depending on their particle size and shape. The characteristics of CQDs are mainly governed by their surface chemistry, and the ligand exchange process plays a crucial role in determining their surface states. Worldwide studies toward the realization of high-quality quantum dots have led to advances in ligand exchange methods, and these procedures are usually carried out in either solid-state or solution-phase. In this article, we review recent advances in solid-state and solution-phase ligand exchange processes that enhance the performance and stability of lead sulfide (PbS) CQD solar cells, including infrared (IR) CQD photovoltaics.
关键词： solar cell,quantum dots,ligand exchange,PbS
更新于2025-09-19 17:13:59
-
PbE (E = S, Se) Colloidal Quantum Dot-Layered 2D Material Hybrid Photodetectors
摘要： Hybrid lead chalcogenide (PbE) (E = S, Se) quantum dot (QD)-layered 2D systems are an emerging class of photodetectors with unique potential to expand the range of current technologies and easily integrate into current complementary metal-oxide-semiconductor (CMOS)-compatible architectures. Herein, we review recent advancements in hybrid PbE QD-layered 2D photodetectors and place them in the context of key findings from studies of charge transport in layered 2D materials and QD films that provide lessons to be applied to the hybrid system. Photodetectors utilizing a range of layered 2D materials including graphene and transition metal dichalcogenides sensitized with PbE QDs in various device architectures are presented. Figures of merit such as responsivity (R) and detectivity (D*) are reviewed for a multitude of devices in order to compare detector performance. Finally, a look to the future considers possible avenues for future device development, including potential new materials and device treatment/fabrication options.
关键词： photodetectors,phosphorene,infrared,PbS,graphene,layered 2D materials,TMDs,colloidal quantum dots,PbSe
更新于2025-09-19 17:13:59
-
Passivation via atomic layer deposition Al2O3 for the performance enhancement of quantum dot photovoltaics
摘要： PbS colloidal quantum dot solar cells (CQDSCs) are promising photovoltaic devices with a broad spectral response, solution processability and long-term air stability. Recently, major progresses have been achieved in the performance enhancement of CQDSCs through the chemical surface passivation of CQDs and the device engineering. However, the p-type PbS-EDT hole extraction layer presents high surface-trap density, which induces charge recombination risk and blocks the hole extraction at the PbS-EDT/Au interface. Herein, we demonstrated a method to passivate the surface traps of PbS-EDT film by post-depositing an aluminum oxide (Al2O3) layer using atomic layer deposition (ALD) technology. The ALD progress was carefully controlled to ensure that ALD Al2O3 could overcoat and infill the PbS-EDT film at the same time. This ALD Al2O3 treatment efficiently passivated the surface traps of PbS-EDT and successfully kept the proper band alignment at PbS-TBAI/PbS-EDT interface for the fast hole extraction of CQDSCs. Consequently, this method allowed the efficient carrier extraction at the PbS-EDT/Au interface through suppressing trap-induced reverse Schottky barrier. A power conversion efficiency of 7.07% was finally obtained in the PbS CQDSCs with ALD Al2O3.
关键词： PbS quantum dot solar cells,Atomic layer deposition Al2O3,Passivation,Traps
更新于2025-09-19 17:13:59
-
Aga??doped PbS thin films by nebulizer spray pyrolysis for solar cells
摘要： Silver (Ag)-doped PbS (PbS:Ag) thin films of 616 to 745 nm in thickness were prepared on glass substrates via cost-effective nebulizer spray method by adding different Ag levels from 2% to 8% at 200°C. For solar cell applications, the effect of Ag doping concentration on structural, morphological, optical, photoluminescence, and electrical chattels of PbS thin film has been studied. X-ray diffraction pattern confirmed the polycrystalline behavior of the prepared PbS:Ag films with cubic crystalline nature. The crystalline size and texture coefficient were increased by increasing Ag doping concentration. From the morphological studies by scanning electron microscope (SEM) and atomic force microscope (AFM), the grain size of the films and surface roughness values were increased for the increase in Ag doping concentration. EDS spectra confirmed the existence of Ag, Pb, and S elements in the select 6% Ag-doped PbS film. Peaks related to silver oxide started to emerge at 6% of Ag doping level. The optical direct band gap value was reduced from 1.51 to 1.17 eV for Ag doping from 2% to 6% and thereby slightly increased as 1.79 eV for 8% Ag doping level. For all PbS:Ag films, the photoluminescence spectrum emitted a strong near band edge (NBE) emission at approximately 580 nm, meaning better optical quality. Hall effect measurements evidenced that Ag doping provides enhancement on the characteristics of mobility, carrier concentration, and resistivity with p-type conducting nature. The observed high carrier concentration and low resistivity values were 4.32 × 1014 cm?3 and 80 Ωcm, for 6% Ag-doped PbS film. The FTO/CdS/PbS:Ag heterostructure solar cell was formed from 6% Ag-doped film.
关键词： XRD,hall effect,thin film,PbS:Ag,solar cell
更新于2025-09-19 17:13:59
-
Dynamic Ligand Surface Chemistry of Excited PbS Quantum Dots
摘要： The ligand shell around colloidal quantum dots mediates the electron and energy transfer processes that underpin their use in optoelectronic and photocatalytic applications. Here, we show that the surface chemistry of carboxylate anchoring groups of oleate ligands passivating PbS quantum dots undergoes significant changes when the quantum dots are excited to their excitonic states. We directly probe the changes of surface chemistry using time-resolved mid-infrared spectroscopy that records the evolution of the vibrational frequencies of carboxylate groups following excitation of the electronic states. The data reveal a reduction of the Pb?O coordination of carboxylate anchoring groups to lead atoms at the quantum dot surfaces. The dynamic surface chemistry of the ligands may increase their surface mobility in the excited state and enhance the ability of molecular species to penetrate the ligand shell to undergo energy and charge transfer processes that depend sensitively on distance.
关键词： surface chemistry,PbS quantum dots,ligand shell,colloidal quantum dots,time-resolved mid-infrared spectroscopy
更新于2025-09-19 17:13:59
-
Optical Properties of PbS Quantum Dots deposited on Glass Employing a Supercritical CO2 Fluid Process
摘要： We studied the temperature dependence of the emission and absorption of PbS quantum dots deposited on glass by a supercritical CO2 fluid process. The results show that the emission is ruled by different transitions than the absorption, particularly at cryogenic temperatures. We found indications that these observations can be linked to the PbS concentration used to form the films in conjunction with the capability of the supercritical CO2 method to form dense homogeneous films.
关键词： absorption,photoluminescence,supercritical fluid deposition,temperature dependent,PbS
更新于2025-09-19 17:13:59
-
Inverted Si:PbS Colloidal Quantum Dots Heterojunction Based Infrared Photodetector
摘要： Silicon and PbS colloidal quantum dots heterojunction photodetector combines the advantages of Si device and PbS CQDs, presenting a promising strategy for infrared light detecting. However, the construction of high quality CQDs:Si heterojunction remains to be a challenge. In this work, we introduce an inverted structure photodetector based on n-type Si and p-type PbS CQDs. Compared with the existing normal structure photodetector with p-type Si and n-type PbS CQDs, it has lower energy band offset which provides higher efficient charge extraction for device. With the help of Si wafer surface passivation and the Si doping density optimization, the device delivers a high detectivity of 1.47×1011 Jones at 1540 nm without working bias, achieving the best performance in Si/PbS photodetectors now. This work provides a new strategy to fabricate low cost high performance PbS CQDs photodetector compatible with silicon arrays.
关键词： PbS CQDs,heterojunction,silicon,photodetector,ROICs
更新于2025-09-19 17:13:59
-
Effect of molarities on structural and optical properties of type-II heterostructure CdS/PbS core/shell quantum dot
摘要： The interrelation between particle sizes and crystal structure in core/shell (CS) semiconductor quantum dots has elicited widespread interest. The effects of precursor concentration of chemically synthesized CdS/PbS CS nanoparticles on structural and optical properties have been reported. CdS/PbS CS QDs shows polycrystalline nature with hexagonal phase in X-ray Diffraction (XRD) pattern, which was also confirmed from SEAD pattern. The particle size was found about 15 nm from the HRTEM images, which was also exhibited CS structure of the NPs. EDX and XRD pattern exhibited the formation of pure CdS/PbS CS structure NPs. The strain in the small spherical NPs is dominant; resulting is shifting of XRD peaks towards higher 2θ values and is found to decrease with an increased crystal size of the core. The effect of molarities on the size of the NPs has seen in the absorption spectra and emission spectra with red shifted. The bandgap of the CS NPs varies inversely with the molar concentration of the nanocrystals. The luminescence intensity exhibited increasing trend with the molar concentration of the nanocrystals. The optical properties were found to be in agreement with the structural properties of the CS NPs.
关键词： Molarities effect,Structural properties,Optical properties,CdS/PbS,Core/shell nanoparticles
更新于2025-09-16 10:30:52
-
[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Effect of tapered fiber structure on the PbS Nanomaterials optical fiber amplifier excited by evanescent wave
摘要： PbS nanomaterials fiber amplifier was fabricated by coating PbS nanomaterials onto tapered fiber. PbS is deposited by atomic layer deposition technique. The influence to optical properties is discussed when changing the structure of tapered fiber.
关键词： optical fiber amplifier,atomic layer deposition,PbS nanomaterials,tapered fiber
更新于2025-09-16 10:30:52