CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Weizhi Zhang,Taiyang Zhang,Lixia Qin,Shi-Zhao Kang,Yixin Zhao,Xiangqing Li
The purity of PbI 2 plays a critical role in determining the performance, stability, and reproducibility of perovskite solar cells (PSCs). However, the cost of high-purity PbI 2 is much higher than that of low-purity, and even the expensive high-purity PbI 2 suffers from batch variance issues. Although several purification methods have been developed, the straightforward and rapid purification of PbI 2 remains a challenge. The solar cell efficiency achieved by previous direct purification of PbI 2 is much lower than the state-of-the-art value. Therefore, people still doubt whether the low-purity PbI 2 is eligible for the fabrication of efficient solar cells even after purification. Herein, we report an anti-solvent engineering strategy for the rapid and facile purification of low-purity PbI 2 , which allows us to efficiently eliminate both the insoluble and soluble impurities. Eventually, the formamidinium-cesium (FA 0.95 Cs 0.05 PbI 3 ) PSCs made from directly purified PbI 2 show much enhanced performance and reproducibility. A champion power conversion efficiency of 23.91% is realized, which is the highest value ever reported for PSCs made from purified low-purity PbI 2 . The in-depth PbI 2 purification mechanism is further discussed from the perspective of solvent-coordination and solvent–solvent interactions by combining the donor number (D N ) value of solvents and Hansen solution parameters. The results reveal that the weaker interaction between PbI 2 and solvent, together with the stronger interaction between solvent and anti-solvent, is crucial for achieving successful purification. This study not only provides a simple and rapid method for the purification of PbI 2 but also enhances our understanding of the selective crystallization of PbI 2 and perovskite by elucidating the solvate and de-solvation processes of PbI 2 within the perovskite precursor.
研究领域:
材料科学
·
化学工程
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
Materials Chemistry Frontiers
·
2017
·Vol. 2
·期 2
·362-368
·
IF 0
Chong Hu,Tao Ye,Yujing Liu,Jie Ren,Xinyi Jin,Hongzheng Chen,Hanying Li
Incorporation of guest materials into semiconducting single crystalline hosts leads to the formation of semiconducting single-crystal composites. However, limited efforts have been made to comprehensively investigate the property of these potential functionalized single-crystal composites. Herein, PbI2/gel single-crystal composites have been successfully prepared. Diffuse reflectance spectra show a clear increase in the band gap of PbI2 after gel incorporation. The band gap is further increased through expanding the area of host/guest interfaces or enhancing the interatomic forces at the interfaces. The interatomic forces (electrostatic interaction) at the host/guest interfaces are attributed to this band gap shift. As such, this study provides a novel and facile way for band gap engineering by gel incorporation.
研究领域:
材料科学
·
半导体物理
✓ 已验证
DOI
JOURNAL OF RAMAN SPECTROSCOPY
·
2020
·Vol. 52
·期 2
·491-496
·
IF 2
Lin Zhu,Hao Ma,Wei Song,He Wang,Peng Li,Chao Ma,Jiawei Wu,Lin Guo,Bing Zhao
Intercalation, the insertion of guest atomic and molecular entities into the architecture of a crystal, is an efficient route for generating new materials with novel properties. However, the detailed analysis of their new structure and properties is of great importance, which are still insufficient. Here, 1,2-bis(4-pyridyl)ethylene (BPE) intercalated PbI 2 (BIP) has been investigated by Raman spectroscopy together with correlated studies of scanning electron microscope (SEM), X-ray diffraction (XRD), ultraviolet–visible (UV–Vis) absorption spectrum, and energy-dispersive X-ray spectroscopy (EDS). The Raman spectrum of intercalated compound discloses new lines at 83, 222, and 234 cm −1 with remarkable displacement of the bands at 1001, 1200, 1603, and 1640 cm −1 , indicating a formation of a new crystal and the chemical interaction between the nitrogen atom of guest molecules with PbI 2 host material. XRD confirmed the intercalation of guest molecules into a host matrix through the appearance of diffraction lines at lower angles that are corresponding to the enlarged unit cell in c axis. Furthermore, we also found that the PbI 2 can specifically adsorb of BPE molecules, which was confirmed by an adsorption experiment revealed by adsorption capacity toward BPE is higher than 2,2-bipyridine and 4,4-bipyridine, suggesting the good adsorptive selectivity toward BPE by PbI 2 film. This work further demonstrated our mechanism on enhanced Raman spectroscopy on PbI 2 . It is believed that this unusual discovery not only enables PbI 2 to be a specific adsorbent, which also provides a new advance toward a better understanding of structure about PbI 2 .
研究领域:
材料科学
·
光谱学
·
晶体结构
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2024
·
IF 5.4
Shu Tang,Huiying Hao,Boyuan Yang,Wanfei Shi,Shindume Lomboleni Hamukwaya,Jingjing Dong,Jie Xing,Hao Liu
The emergence of CsPbBr3 perovskite solar cells (PSCs) with a band gap of approximately 2.3 eV has generated increasing interest stemming from their potential for high open-circuit voltage (Voc), making them particularly suitable for use in tandem configurations or spectral splitting. However, the Voc of PSCs currently falls short of its theoretical limit, driven by trap-mediated charge recombination and energy band alignment mismatch. In this study, we present a straightforward additive engineering approach involving the introduction of PbI2 species into the PbBr2 precursor film to form the I–Pb–Br interaction, retarding the rapid reaction between PbBr2 and CsBr. This approach effectively suppresses the Pb-rich phase CsPb2Br5, eliminates pinholes on the CsPbBr3 crystal, and obtains high-quality perovskite films, which can significantly enhance the photovoltaic properties. Consequently, we achieved CsPbBr3 films characterized by enlarged crystal size, complete coverage, high purity, and without pinhole presence, leading to a best-performed efficiency of 10.35% and a higher Voc of up to 1.580 V compared to the power conversion efficiency (PCE) of 8.35% and a Voc of 1.442 V of the control device, along with exceptional operational stability.
研究领域:
材料科学
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能源技术
·
光伏研究
✓ 已验证
产品关联
DOI
高影响因子
Solar RRL
·
2018
·Vol. 2
·期 12
·1800230
·
IF 0
Zhongze Liu,Kaimo Deng,Yayun Zhu,Meng Wang,Liang Li
The quality of the perovskite film has a vital influence on the performance of perovskite solar cells and it is quite desirable to simultaneously manipulate the crystallization and morphology of the perovskite film. In this study, conventional PbI 2 is replaced with a PbI 2 /I 2 mixed precursor during the first step of sequential deposition, causing the formation of a PbI 2 porous nanostructure. By changing the content of I 2 in the precursor, the morphology of the PbI 2 film as well as the resulting perovskite film can be successfully modulated. With an optimal content of I 2 , a high-quality perovskite film with a pure phase and smooth surface can be achieved. As a result, the conversion efficiency of perovskite solar cells using a PbI 2 /I 2 mixed precursor can be as high as 18.63%, compared to 16.89% for the reference device through traditional sequential deposition with a pure PbI 2 precursor.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
Advanced Optical Materials
·
2023
·Vol. 11
·期 6
·2202561
·
IF 9
Liuli Yang,Jianhua Huang,Zheyuan Xu,Yang Li,Shijin Hou,Yike Tan,Juan Du,Xiao Wang,Ziwei Li,Anlian Pan
CsPbI 3 perovskite quantum dots (QDs) are promising materials for high-efficiency and low-cost red fluorophores in advanced display and light-sensing applications. However, structural and spectral stabilities of CsPbI 3 QDs by traditional preparation are seriously broken in water or light environment. Here, a compositional engineering strategy with an additional PbI 2 -recondition process to synthesize highly-stable CsPbBr 1.2 I 1.8 @ SiO 2 QDs is demonstrated. Time- and temperature-dependent photoluminescence and Raman measurements prove that spectral stability and exciton binding energy of QDs are greatly improved within this strategy. Notably, high-resolution structure characterizations, point-to-point diffraction patterns and line-scanning of element distributions provide strong and direct evidence at atomic-level to reveal that PbI 2 -recondition can repair defects well, which helps to construct perfect lattices and homogeneous SiO 2 passivation layers to prevent the surface bonding of molecules. Moreover, our red perovskite QDs are further designed to prepare various anti-counterfeiting labels as multi-scale complex patterns to store and protect information. The proposed recondition strategy explores a new avenue to prepare stable and high-quality red perovskite QDs for new-generation lighting and light-sensing devices.
研究领域:
材料科学
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光学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2022
·Vol. 157
·期 19
·
IF 4.304
Xu Tie,Cai Hongkun,Ye Xiaofang,Zhu Yinbin,Ni Jian,Li Juan,Zhang Jianjun
Black-phase formamidinium lead iodide (FAPbI 3 ), with a narrow bandgap and high thermal stability, has emerged as an in-demand material for highly efficient perovskite solar cells (PSCs). In a two-step sequential deposition, the PbI 2 film plays an important role in the formation of a perovskite film with desirable qualities. This paper explores using N-methyl-2-pyrrolidone (NMP), a strong Lewis base, and N,N-dimethylformamide (DMF) as a mixed precursor solvent (DMF/NMP) of PbI 2 and reports on preparing PbI 2 films with a porous morphology by thermal treatment. Porous PbI 2 films ensure the diffusion and sufficient reaction of the formamidinium iodide solution to form a smooth perovskite film. In addition, a dynamic spin coating method is also introduced to improve the uniformity of the perovskite film. Both methods yield a pure α-phase FAPbI 3 film immediately in the unannealed state, which is necessary for the perovskite film to maintain phase stability. Finally, PSCs with a power conversion efficiency of 21.20% (0.13 cm 2 ) are fabricated and optimized. The unencapsulated PSCs retain 90% of the initial efficiency for 1000 hours in dry air and exhibit a good thermal stability when heated to 85 °C.
研究领域:
材料科学
·
能源技术
·
光伏器件
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
XiuXiu Feng,Jiyao Wei,Xiaodong Li,Wenxiao Zhang,Xiaoyan Zhao,Chunyan Lu,Xuemin Guo,Junfeng Fang
PbI2 is a commonly used passivator for defect passivation in perovskite solar cells (PSCs). However, the poor conductivity nature of PbI2 may limit the further improvement of device performance. Here, we report a radical form of PbI2 with high conductivity to passivate defects for efficient PSCs through a combination of N,N,N′,N′-tetramethylbenzidine (TMB). When PbI2 is combined with TMB, 4 orders of magnitude higher conductivity will be achieved owing to the formation of a TMB-PbI2 radical. As a result, the device performance is impressively increased from 20.48 to 22.63%. In addition, the device stability is also greatly improved and 95% of the initial efficiency is retained after aging at 85 °C for 600 h.
研究领域:
材料科学
·
能源技术
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 4
·505
·
IF 4.034
Jieni Li,Henan Li,Dong Ding,Zibo Li,Fuming Chen,Ye Wang,Shiwei Liu,Huizhen Yao,Lai Liu,Yumeng Shi
We prepared high-performance photoresistors based on CH3NH3PbI3films with a high PbI2doping level. The role of PbI2in CH3NH3PbI3perovskite thin film was systematically investigated using scanning electron microscopy, X-ray diffraction, time-resolved photoluminescence spectroscopy, and photoconductive atomic force microscope. Laterally-structured photodetectors have been fabricated based on CH3NH3PbI3perovskite thin films deposited using precursor solution with various CH3NH3I:PbI2ratios. Remarkably, the introduction of a suitable amount of PbI2can significantly improve the performance and stability of perovskite-based photoresistors, optoelectronic devices with ultrahigh photo-sensitivity, high current on/off ratio, fast photo response speed, and retarded decay. Specifically, a highest responsivity of 7.8 A/W and a specific detectivity of 2.1 × 1013Jones with a rise time of 0.86 ms and a decay time of 1.5 ms have been achieved. In addition, the local dependence of photocurrent generation in perovskite thin films was revealed by photoconductive atomic force microscopy, which provides direct evidence that the presence of PbI2can effectively passivate the grain boundaries of CH3NH3PbI3and assist the photocurrent transport more effectively.Keywords:high PbI2doping content;PC-AFM;photoresistor;grain boundary passivation
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Chemistry
·
2021
·
IF 9.676
Zhu Ma,Dejun Huang,Qianyu Liu,Guangyuan Yan,Zheng Xiao,Dong Chen,Jiaxuan Zhao,Yan Xiang,Changtao Peng,Haijin Li,Meng Zhang,Wenfeng Zhang,Lianfeng Duan,Yuelong Huang
The triple cation mixed perovskites (CsFAMA) are known as one of the most efficient candidates for perovskite solar cells (PSCs). It is found that the power conversion efficiency (PCE) of triple-cation based devices would increase with the test time extending, and the maximum efficiency is normally obtained after several days aging storage. Here, the relationship between enhanced device performance, excess PbI 2 and its evolution in triple cation perovskite films of initial days was systematically explored. The CsFAMA-PSCs are prepared by two-step methods under two environmental conditions, including in the glove box and the ambient air (30% humidity). After 7 days testing, the maximum PCE of PSCs under two conditions dramatically increased 12.4% and 12.2%, reached 21.68% and 21.89%, respectively. At initial days, the XRD peak intensities of perovskite phase gradually decreased and those corresponding to PbI 2 increased. Along with time-resolved photoluminescence (TRPL) and kelvin probe force microscopy (KPFM), it was found that the defects were passivated with the evolution of PbI 2 . This work reveals the excess PbI 2 and its evolution in perovskite film, which can further supplement the understanding of PbI 2 defect passivation.
研究领域:
材料科学
·
光伏技术
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Rui Li,Huanyu Zhang,Mei Zhang,Min Guo
The morphology of perovskite layer is a deterministic factor in determining photovoltaic performance of perovskite solar cells (PSCs). In this paper, by using two-step spin-coating method, different electron donating ability solvents including DMF, DMF + CH 3 COCH 3 , DMF + DMSO + HAc, DMSO + HAc and DMSO + ACN were selected to investigate the nucleation and growth mechanism of PbI 2 adduct and perovskite film by X-ray diffraction (XRD), scanning electron microscopy (SEM) and time-resolved-photoluminesence (TRPL). The solution DMSO + ACN was chosen as the optimal solvent due to its higher performance of the constructed device. Moreover, the effect of volume ratio of DMSO to ACN ( V DMSO/ACN ) on the perovskite film was systematically studied. The results indicated that more compact perovskite film with larger grain size could be formed with ACN amount increasing, which led to higher power conversion efficiency (PCE) of the solar cell. Dynamic light scattering (DLS) analysis of PbI 2 /DMSO + ACN solutions was used to elucidate the phenomenon. With ACN amount increasing from 19:1 to 7:3, the radius of ACN-PbI 2 -DMSO clusters in solutions decreased from 694.2 to 365.1 nm, resulting in formation of porous PbI 2 adduct films, thus providing MAI solution more transport channels and adequate space for grain growth. Under the air relative humidity of 30%, the device PCE of 15.32% was achieved at the V DMSO/ACN of 7:3.
研究领域:
材料科学
·
太阳能技术
✓ 已验证
DOI
高影响因子
Small
·
2023
·
IF 13.3
Xi Yu,Zhenxing Fang,Siyuan Lin,Shuyue Wu,Mei Fang,Haipeng Xie,Deming Kong,Conghua Zhou
Polyvinyl pyrrolidone is blended in PbI 2 with varied concentration, so as to study the coarsening dynamics of perovskite during the two-step growth method. It is observed that polyvinyl pyrrolidone hinders the crystallization of PbI 2 and helps to form a more amorphous PbI 2 matrix, which then improves perovskite crystallization. As the blending concentration increases from 0 to 2 mM, average crystallite/grain size of perovskite increases from 40.29 nm/0.79 µm to 84.35 nm/1.02 µm while surface fluctuation decreases slightly from 25.64 to 23.96 nm. The observations are caused by the “confinement effect” brought by polyvinyl pyrrolidone on PbI 2 . Elevating blending concentration of polyvinyl pyrrolidone results in smaller PbI 2 crystallites and more amorphous PbI 2 matrix, thus reducing the diffusion/reaction barrier between PbI 2 and organic salt and favoring perovskite crystallization. As blending concentration increases from 0 to 2 mM, the device efficiency rises from 19.76 (± 0.60) % to 20.50 (± 0.89) %, with the optimized value up to 22.05%, which is further improved to 24.48% after n-Octylammonium iodide (OAI)-basing surface modification. The study enlarges the scope of “confinement effect” brought by polymer molecules, which is beneficial for efficient and stable perovskite solar cell fabrication.
研究领域:
材料科学
·
太阳能电池技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）