OPTICAL MATERIALS
·
2021
·
IF 3.08
Rui Qu,Mingyang Gao,Haonan Li,Xiaofei Qi,Cheng Liu,Wu Zhao,Junfeng Yan,Zhiyong Zhang
Formamidinium lead bromide perovskite (FAPbBr 3 ) nanostructures have aroused increasing attention considering their excellent optoelectronic performance and higher stability than their MA- and Cs-based counterparts. Herein, we synthesized size-tunable FAPbBr 3 quantum dots (QDs) at room temperature. The size of the perovskite QDs could be ajusted from 5.4 to 2.3 nm by just varying the amount of Hydrobromic Acid (HBr) added into the precursor. As a result, the photoluminescence (PL) emissions exhibited large blueshift from 531 to 446 nm due to quantum confinement effect. Quantum mechanical calculations of the optical gap fitted well with the experimental results. We found that the addition of HBr not only increased the concentration of the Br − but also protonated the oleylamine ligands. The two events synergically governed the size-decreasing effect of the QDs with increasing amount of HBr. The size-tunable FAPbBr 3 QDs showed great application prospect in the field of photoelectric devices.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Benjun Huo,Jie Yang,Yao Bian,Daofu Wu,Julin Feng,Jiaer Zhou,Qiang Huang,Fan Dong,Xiaosheng Tang
The superior optical properties and adjustable bandgap allows for hybrid halide perovskite quantum dots to be promising photocatalytic materials, but the serious radiative recombination and instability inhibit the improvement of photocatalytic conversion efficiency. Herein, we successfully synthesized the FAPbBr 3 /A-SiO 2 nanocomposites photocatalyst by anchoring formamidinium (FA + , HC(NH 2 ) 2+ ) lead halide perovskite quantum dots on aminated silica spheres to construct the composite photocatalysts via N H chemical bonding. The FAPbBr 3 /A-SiO 2 composites show the significantly enhanced visible-light-driven NO removal activity (70%) compared to the pristine FAPbBr 3 (30%) in half an hour at room temperature, revealing that the increased active sites and efficient charge carrier separation contribute to the absorption and activation of reactant molecules. This work would open the new possibilities for improving the photocatalytic ability of perovskite quantum dots.
研究领域:
材料科学
·
环境科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2018
·Vol. 10
·期 44
·20611-20617
·
IF 7.233
Feiming Li,Lan Yang,Zhixiong Cai,Ke Wei,Fangyuan Lin,Jie You,Tian Jiang,Yiru Wang,Xi Chen
Formamidinium lead bromide perovskite nanocrystals (FAPbBr3 PNCs) are extremely promising for applications in green light emitting diodes (LEDs) since their photoluminescence maxima locate in the range of 530–535 nm with a narrow full width at half-maximum (<25 nm). However, the low exciton binding energy (EB) of FAPbBr3 (∼25 meV) hinders its development in LEDs. In this study, we have developed a 2-methyl-1-pentanol assisted hot injection method for the synthesis of 2D FAPbBr3 nanoplates with high stability. Due to strong quantum confinement in two dimensions of the nanoplates, the obtained FAPbBr3 nanoplates exhibited a high EB of 168.4 meV. The high EB dramatically enhances the photoluminescence (PL) properties with a high fluorescence quantum yield of 92%, which realizes a long photoluminescence lifetime of 2 ns with negligible trapping processes. Benefiting from the high EB and outstanding PL properties, the FAPbBr3 nanoplate LED device showed a current efficiency of 17.32 cd A−1 at a low voltage of 4 V, and a corresponding external quantum efficiency (EQE) up to 4.5% with the Commission Internationale de L'Eclairage (CIE) 1931 color coordinates of (0.24, 0.73), providing a new pathway for the fabrication of efficient perovskite based LED devices.
研究领域:
材料科学
·
光学工程
·
电子器件
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Meidan Que,Yang Zhao,Yawei Yang,Longkai Pan,Wanying Lei,Weihua Cai,Hudie Yuan,Jin Chen,Gangqiang Zhu
Metal halide perovskite with a suitable energy band structure and excellent visible-light response is a prospective photocatalyst for CO2 reduction. However, the reported inorganic halide perovskites have undesirable catalytic performances due to phase-sensitive and severe charge carrier recombination. Herein, we anchor the FAPbBr3 quantum dots (QDs) on Ti3C2 nanosheets to form a FAPbBr3/Ti3C2 composite within a Schottky heterojunction for photocatalytic CO2 reduction. Upon visible-light illumination, the FAPbBr3/Ti3C2 composite photocatalyst exhibits an appealing photocatalytic performance in the presence of deionized water. The Ti3C2 nanosheet acts as an electron acceptor to promote the rapid separation of excitons and supply specific catalytic sites. An optimal electron consumption rate of 717.18 μmol/g·h is obtained by the FAPbBr3/0.2-Ti3C2 composite, which has a 2.08-fold improvement over the pristine FAPbBr3 QDs (343.90 μmol/g·h). Meanwhile, the FAPbBr3/Ti3C2 photocatalyst also displays a superior stability during photocatalytic reaction. This work expands a new insight and platform for designing superb perovskite/MXene-based photocatalysts for CO2 reduction.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2020
·Vol. 8
·期 6
·1901390
·
IF 8.286
Hongting Chen,Lianwei Fan,Rui Zhang,Chunxiong Bao,Haifeng Zhao,Wei Xiang,Wei Liu,Guangda Niu,Runda Guo,Louwen Zhang,Lei Wang
Formamidinium lead bromide (FAPbBr 3 ) nanocrystals (NCs) demonstrate great potential in light-emitting diode (LED) applications due to their pure green emission and excellent stability. However, the abundant defects at the surface of the NCs act as charge trapping centers and significantly increase the trap-assisted nonradiative recombination channels, hampering the performance improvement of LEDs based on FAPbBr 3 NCs. Herein, a facile self-passivation strategy of the surface defects is developed by introducing excess formamidinium bromide (FABr) during the colloidal synthesis of NCs, leading to much improved photoluminescence quantum yield (PLQY) of the obtained NCs. In addition, enhanced charge transport property is measured in the assembled films owing to the simultaneously declined insulating ligands at the surface of NCs. The molar ratio of FABr and PbBr 2 is rationally optimized during the synthesis of NCs and high-efficient green-emissive LEDs are fabricated with a champion current efficiency of 76.8 cd A −1 , corresponding to an external quantum efficiency of 17.1%, which is among the best-performing green LEDs based on perovskite NCs so far.
研究领域:
材料科学
·
光电技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Liya Cao,Shuangshuang Shi,Fangfang Li,Zhongzhi Tian,Shu Xu,Chong Geng
Formation of organometal lead halide perovskite nanocrystals (OPNCs) occurs in fast time scales from milliseconds to seconds, thus posing a hurdle to the growth kinetic study of OPNCs. Water-oil interfacial reaction provides an effective approach for retarding the growth of CH 3 NH 3 PbBr 3 OPNCs. Herein, we investigate systematically the kinetics of CH 3 NH 3 PbBr 3 NCs in water–oil reaction by in situ optical characterization, and identify the key factors governing the growth of OPNCs. Molecular polarity and viscosity of the solvent are found to be crucial to the diffusion step by affecting the diffusion coefficient of CH 3 NH 3 + . Covalent characteristic of the Pb source and molecular structure of the ligands have an impact on the rate-limiting step of PbBr 6 4- formation. In addition, we establish the reaction condition that enables controlled growth of formamidinium lead bromide NCs, thereby demonstrating the application of the growth kinetic in the synthesis of other OPNCs. Kinetic investigation of OPNCs provides a better understanding of their crystallization process that helps guide the development of quantum confined OPNCs for optoelectronic applications.
研究领域:
材料科学
·
纳米技术
·
光电子学
·
化学动力学
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC ELECTRONICS
·
2018
·
IF 3.68
Lianwei Fan,Ke Ding,Hongting Chen,Songpo Xiang,Rui Zhang,Runda Guo,Zhitian Liu,Lei Wang
Formamidinium (FA) lead bromide (FAPbBr 3 ) perovskite nanocrystals (P-NCs) have ultrapure green emission and high stability, while FAPbBr 3 NCs based light-emitting diodes (FA-NLEDs) still have little report. Here, FAPbBr 3 NCs with a high photoluminescence quantum yield of 85.8% were synthesized. By controlling the concentration of FAPbBr 3 NCs in toluene solution, the exciton recombination region was precisely confined to the emitting layer and the parasitic emission coming from electron transport layer disappeared, resulting in the pure green emissions. The optimized FA-NLED presents a maximum external quantum efficiency (EQE), current efficiency (CE) of 3.84% and 16.08 cd/A respectively, with the EL emission peak of 528 nm, CIE of (0.183, 0.763) and a full width of half-maximum (FWHM) of 24 nm, which is among the best performance of FA-NLEDs.
研究领域:
材料科学
·
光电技术
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）