Nanoscale
·
2020
·Vol. 12
·期 16
·9231-9239
·
IF 6.895
Xiaolin Xiao,Ye Li,Rong-Jun Xie
Low dimensional semiconductor nanomaterials show great promise for a variety of applications due to their size-dependent and excellent optoelectronic properties. In this work, we developed a strategy to synthesize uniform and very thin CsPbBr3 perovskite nanoplates (NPls) by introducing additional metal bromides. The CsPbBr3 NPls, self-assembled into a face-to-face stacked state, had a thickness of 4.4 nm (equal to only 2 monolayers, 2 MLs) and showed a maximum emission at 437 nm and a narrow FWHM of 14 nm. The formation mechanism of the CsPbBr3 NPls by adding FeBr3 was ascribed to the constrained growth of CsPbBr3 nanocubes when the surface Cs+ ions were substituted by the protonated oleylammonium from the byproduct OLA-HBr.
研究领域:
材料科学
·
纳米技术
·
光电子学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Zhijie Zhang,Liang Li,Ying Jiang,Jiayue Xu
Heterojunction manipulation has been deemed as a promising approach in exploring efficient photocatalysts for CO2 reduction. In this article, a novel step-scheme (S-scheme) photocatalyst of CsPbBr3 quantum dots/BiOBr nanosheets (CPB/BiOBr) was fabricated via a facile self-assembly process. The strong interaction, staggered energy band alignments, and much different Fermi levels between CsPbBr3 and BiOBr promised the formation of an S-scheme heterojunction. The resultant CPB/BiOBr heterojunction delivered remarkable photocatalytic performance in CO2 reduction, with an electron consumption rate of 72.3 μmol g–1 h–1, which was 4.1 and 5.7 times that of single CsPbBr3 and BiOBr, respectively. The superior photocatalytic performance originated from the impactful spatial separation of photoinduced electron–hole pairs, as well as the preservation of strongly reductive electrons for CO2 reduction. This work offers a rational strategy to design S-scheme heterojunctions based on lead halide perovskites, which are expected to have potential applications in the field of photocatalysis and solar energy utilization.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Yanyan Duan,Gen Zhao,Xiaotao Liu,Jiale Ma,Shuyao Chen,Yanlin Song,Xiaodong Pi,Xuegong Yu,Deren Yang,Yiqiang Zhang,Feng Guo
High power conversion efficiency (PCE) and good long-term stability are everlasting pursuit for perovskite solar cells. We present here CsPbBr 3 perovskite film deposited by vacuum co-evaporation of CsBr and PbBr 2 . By optimizing evaporation rate ratio of the two precursor and annealing temperature, perovskite films with large grain and high crystallinity are obtained. Furthermore, by regulating spinning speed of TiO 2 precursor solution and thickness of CsPbBr 3 film, a best PCE of 9.43% is recorded under 100 mW cm −2 illumination, providing a significant enhancement in contrast with 6.26% of device based on spin-coating method. Additionally, the PCE of resulting perovskite solar cell without encapsulation remains at 96% of initial value after storing for 480 h under humidity of 40% in air. Our findings in this work deliver an effective strategy to fabricate high-performance inorganic perovskite solar cells.
研究领域:
材料科学
·
太阳能技术
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 13
·135701
·
IF 3.874
Aiqing Zhao,Yuhang Sheng,Cihui Liu,Songyan Yuan,Xiaoli Shan,Yunsong Di,Zhixing Gan
During synthesis, device processes, and applications of perovskite nanocrystals (NCs), there are usually inevitable interactions between perovskite NCs and polar solvents. To elaborately control the properties of perovskite NCs, investigating the effects of solvent polarity on perovskite NCs is thus highly important. Herein, fluorescent variations induced by different solvents into CsPbBr3 NCs solution are systematically studied. In this report, it is found that when CsPbBr3 NCs are treated with polar solvents, the fluorescence intensity decreases with a general redshift of fluorescence peak position. Moreover, the fluorescence quenching and peak position shift amplitude monotonously increase with the solvent polarity. Absorption spectra and fluorescent lifetime suggest that, with addition of polar solvents, the surface of NCs are destroyed and defect states are generated, leading to the fluorescent variations. Besides, dielectric constant of the solvent also increases with polarity, which may weaken the quantum confinement effect and decrease the exciton binding energy. We find the fluorescence may slightly blue shift if the emission of free carrier is strong enough with certain solvents, such as dimethylsulfoxide (DMSO). We also find the fluorescence intensity generally deceases to a stable state in 2 min, indicating quick interactions between CsPbBr3 NCs and solvents. However, water continuously quenches the fluorescence of CsPbBr3 NCs up to 72 h due to the poor miscibility between water and n-hexane. This work not only provides a comprehensive understanding on the fluorescent dynamics of CsPbBr3 NCs in polar solvents but also affords a potential fluorescent indicator for solvent polarity.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2020
·
IF 4.189
Keisei Shibata,Jiyu Yan,Yuji Hazama,Shaoqiang Chen,Hidefumi Akiyama
This is the first study of lead halide perovskites (LHPs) that compares the coupling strengths between longitudinal optical (LO) phonons and free or localized excitons. In this research, we measured the excitation density and temperature dependence of the photoluminescence (PL) spectra in the range of 4-300 K in a CsPbBr3 single crystal. The PL peak energy of the free excitons monotonically blueshifts when the temperature increases, and so does the localized excitons until the temperature reaches 80 K. Above 80 K, however, the PL peak energy of the localized excitons redshifts when the temperature increases. We analyzed this unique temperature dependence using the configuration coordinate model, focusing on the exciton - LO phonon interaction. We showed that this unique temperature dependence can be exhibited as the localized excitons couple with the LO phonons with enhanced strength and have larger relaxation energy than the free excitons.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Science Bulletin
·
2020
·
IF 9.511
Jianyong Feng,Xiaopeng Han,Huiting Huang,Qingxiao Meng,Zhi Zhu,Tao Yu,Zhaosheng Li,Zhigang Zou
Inorganic lead halide perovskite CsPbBr 3 offers attractive photophysical properties and phase stability for high-performance optoelectronic devices. However, CsPbBr 3 films produced by the classic solution-based two-step method are always accompanied with impurity phases of CsPb 2 Br 5 and Cs 4 PbBr 6 , which represents a major efficiency-limiting factor for future advances of CsPbBr 3 -based devices. The challenge lies in the complexity of the Cs-Pb-Br phase system, requiring both spatially and temporally precise control of the precursor stoichiometry during solution-phase growth of CsPbBr 3 films. By adopting 2-methoxyethanol as the solution conversion medium instead of commonly applied methanol, the reaction between CsBr and PbBr 2 can be finely controlled to yield single phase CsPbBr 3 films within a few minutes; extending the solution-conversion step to 24 h does not alter the phase purity of resulting CsPbBr 3 films. The present work paves the way to regulate the crystal growth behaviors of two-step solution-processed CsPbBr 3 films by simple solvent engineering.
研究领域:
材料科学
·
光电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Zhousu Xu,Yijian Yang,Peng Wang,Xiaofeng Liu,Jianrong Qiu
Nd 3+ co-doped CsPbBr 3 perovskite quantum dots (PQDs) glasses were prepared by conventional melt-quenching followed by a thermal treatment process. With the introduction of Nd 2 O 3 to the parent glass, the optical properties of the CsPbBr 3 PQDs are significantly improved. The energy transfer from CsPbBr 3 PQDs to Nd 3+ ions was investigated and confirmed by excitation and emission spectra. The results show that visible excitation band width for the near-infrared (NIR) emission of Nd 3+ ions is significantly increased in the presence of PQDs. The strategy for modulation of the optical properties by the energy transfer between rare earth ions and PQDs in the glass matrix could be further utilized for spectral engineering of photonic glasses for optoelectronic applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Junjie Lou,Bing Cai,Yihui Wu,Yinhua Lv,Xinhang Liu,Wen-Hua Zhang,Yong Qin
All-bromide inorganic perovskite CsPbBr 3 has attracted enormous attention due to its excellent stability against thermal and high humidity environmental conditions. The wide bandgap of CsPbBr 3 (2.3 eV) makes it a promising material for tandem and semitransparent solar cells. However, cesium based inorganic perovskite solar cells (PSCs) usually suffer from low device performance because of their imperfect film quality and mismatched energy levels with respect to charge transport materials. Herein, we describe a post-treatment strategy for CsPbBr 3 films using formamidinium bromide (FABr). With this protocol, FA + can partially substitute Cs + in the bulk phase of CsPbBr 3 , improving energy level alignment and enhancing charge extraction. Meanwhile, grain boundaries could be effectively passivated by a second phase (FA y Cs 4−y PbBr 6 ) generated in the ion exchange reaction . As a result, FABr-treated PSC exhibits a champion power conversion efficiency (PCE) of 8.25%, much higher than the pristine device with PCE of 6.74%. This work provides a feasible method to improve device performance of CsPbBr 3 PSCs while maintaining their outstanding stability.
研究领域:
材料科学
·
光伏技术
·
化学工程
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2025
·
IF 4.6
Yulin Tan,Ziye Shen,Ying Yang,Huimin Zhang,Yufang Xie,Chenglin Zhang,Yuan Liu,Mingming Chen,Dawei Cao
Heterojunction engineering significantly enhances photocatalytic CO 2 reduction performance. However, a large lattice mismatch in heterostructures hinders photocatalytic reaction by forming extensive grain boundaries, inefficient interfaces, and sluggish interfacial charge transfer. Metal halide perovskites, featuring soft lattices induced by weak ionic metal-halide bonds, offer effective solutions to alleviate such mismatches. Herein, we fabricate BaTiO 3 /CsPbBr 3 photocatalysts with a precisely engineered type-II heterojunction. Notably, the BaTiO 3 /CsPbBr 3 heterostructure achieves a CO formation rate of 17.3 μmol∙g −1 h −1 — 5.2-fold and 2.3-fold higher than pristine BaTiO 3 (3.3 μmol∙g −1 h −1 ) and CsPbBr 3 (7.6 μmol∙g −1 h −1 ), respectively. This improvement stems from the synergistic effect of enhanced light absorption and charge separation. This work provides fundamental insights for developing high-performance heterojunction photocatalysts.
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC ELECTRONICS
·
2021
·
IF 3.721
Li Xiang,Xuekai Huang,Ya Wang,Zhilong Xin,Gaoda Chai,Yangbing Xu,Kai Wang,Jun Chen,Chuan Liu,Xinwei Wang,Shengdong Zhang,Hang Zhou
X-ray detection is an important technology for medical diagnosis as well as industrial and security inspections. While today's commercial X-ray detectors are bulky, photodetectors based on organic semiconductors have attracted increasing attention owing to their low temperature processing capabilities, flexibility and low cost. Nonetheless, the low X-ray attenuation coefficient of organic semiconductors still hinders their practical application. Herein, a new organic-inorganic hybrid strategy is proposed to improve the X-ray sensitivity of organic photodetectors (OPDs). A solution-processed X-ray sensitive hybrid OPD is fabricated by embedding CsPbBr 3 quantum dots (QDs) into a P3HT:PC 61 BM bulk heterojunction photodiode . The QDs, acting as embedded scintillators in the organic active layer, maintain a high radioluminescence . The proposed hybrid structure enables indirect X-ray detection in a comprehensive manner. These hybrid photodetectors exhibit suppressed dark current densities in the range of tens of picoamperes per square centimeters for different weight ratios of blended QDs. The best OPD achieves a sensitivity of 229.6 e nGy −1 mm −2 (3.67 μC Gy −1 cm −2 ) and a dark current of 23.3 pA cm −2 at a low operating voltage (−3 V) for 20–80 kV “soft” X-rays, thus representing great potential for the development of next generation low cost, portable, and highly sensitive X-ray detectors.
研究领域:
材料科学
·
医学影像
·
光电技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2020
·
IF 9.567
Zhoujie Chen,Yangguang Hu,Jin Wang,Qing Shen,Yaohong Zhang,Chao Ding,Yu Bai,Guocan Jiang,Zhengquan Li,Nikolai Gaponik
Converting CO2 into chemical fuels with a photocatalyst and sunlight is an appealing approach to address climate deterioration and energy crisis. Metal complexes are superb candidates for CO2 reduction due to their tunable catalytic sites with high activity. The coupling of metal complexes with organic photosensitizers is regarded as a common strategy for establishing photocatalytic systems for visible-light-driven CO2 reduction. While most of the organic photosensitizers generally contain precious metals and are available through onerous synthetic routes, their large-scale application in the photocatalysis is limited. Halide perovskite nanocrystals (NCs) have been considered as one of the most promising light-harvesting materials to replace the organic photosensitizers due to their tunable light absorption range, low cost, abundant surface sites, and high molar extinction coefficient. Herein, we demonstrate a facile strategy to immobilize [Ni(terpy)2]2+ (Ni(tpy)) on inorganic ligand-capped CsPbBr3 NCs and to apply this hybrid as a catalyst for visible-light-driven CO2 reduction. In this hybrid photocatalytic system, the Ni(tpy) can provide specific catalytic sites and serve as electron sinks to suppress electron–hole recombination in the CsPbBr3 NCs. The CsPbBr3-Ni(tpy) catalytic system achieves a high yield (1724 μmol/g) in the reduction of CO2 to CO/CH4, which is approximately 26-fold higher than that achieved with the pristine CsPbBr3 NCs. This work has developed a method for enhancing the performance of photocatalytic CO2 reduction by immobilizing metal complexes on perovskite NCs. The methodology we present here provides a new platform for utilizing halide perovskite NCs for photocatalytic applications.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2024
·Vol. 160
·期 16
·
IF 3.1
Du Luchao,An Jie,Katayama Tetsuro,Duan Menghan,Shi XiaoPing,Wang Yunpeng,Furube Akihiro
In recent years, all-inorganic perovskite materials have become an ideal choice for new thin film solar cells due to their excellent photophysical properties and have become a research hotspot. Studying the ultrafast dynamics of photo-generated carriers is of great significance for further improving the performance of such devices. In this work, we focus on the transient dynamic process of CsPbBr 3 /TiO 2 composite systems with different Mn 2+ doping contents using femtosecond transient absorption spectroscopy technology. We used singular value decomposition and global fitting to analyze the transient absorption spectra and obtained three components, which are classified as hot carrier cooling, charge transfer, and charge recombination processes, respectively. We found that the doping concentration of Mn 2+ has an impact on all three processes. We think that the following two factors are responsible: one is the density of defect states and the other is the bandgap width of perovskite. As the concentration of doped Mn 2+ increases, the charge transfer time constant shows a trend of initially increasing, followed by a subsequent decrease, reaching a turning point. This indicates that an appropriate amount of Mn 2+ doping can effectively improve the photoelectric performance of solar cell systems. We proposed a possible charge transfer mechanism model and further elucidated the microscopic mechanism of the effect of Mn 2+ doping on the interface charge transfer process of the CsPbBr 3 /TiO 2 solar cell system.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
PubMed
高影响因子
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