Journal of Materials Chemistry A
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2018
·Vol. 6
·期 23
·10947-10957
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IF 9.931
Xiaoqin Sun,Gang Liu,Xiaoxiang Xu
Although SrNbO2N has a promising band gap of ∼1.8 eV for solar water splitting, its photocatalytic activity is generally very poor under ordinary conditions, primarily due to high defect levels caused by synthetic procedures. In this work, we managed to control defect levels inside SrNbO2N by incorporating Mg into the structure, i.e. SrMgx/3Nb1−x/3O2+yN1−y (0 ≤ x ≤ 1). Strikingly, a number of important properties such as band gap value, defect level, nitrogen content and particle size can be tuned by varying the amounts of Mg in the structure. More importantly, efficient photocatalytic water oxidation into oxygen was realized using these Mg modified SrNbO2N. An apparent quantum efficiency (AQE) as high as 5.13% was reached at 420 ± 20 nm for SrMg0.2Nb0.8O2+yN1−y (x = 0.6), which stands as the highest AQE reported to date for SrNbO2N. Mott–Schottky and X-ray photoelectron spectroscopy analyses revealed the shift of valence band maximum of SrNbO2N in response to Mg uptake. Moreover, open-circuit voltage decay measurements confirmed a much prolonged charge lifetime in Mg modified SrNbO2N. Thus, Mg serves not only to tailor band edge positions but also to ameliorate charge separation conditions in SrNbO2N, both of which contribute to the superior photocatalytic activities.
研究领域:
材料科学
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能源化学
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DOI
高影响因子
Solar RRL
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2021
·Vol. 6
·期 1
·2100778
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IF 8.582
Hongling Guo,Rutao Meng,Long Hu,Chun-Ho Lin,Yali Sun,Yue Liu,Jianyu Wu,Zhan Shen,Dewei Chu,Gang Wang,Li Wu,Guangxing Liang,Shifu Xiong,Fangfang Liu,Yi Zhang,Tom Wu
In spite of the merits such as Earth abundance and high performance, Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells suffer from unfavorable Sn Zn antisite defects and complexes, which act as nonradiative recombination centers and deteriorate the open-circuit voltage ( V OC ). Therefore, the management of Sn composition is the prerequisite for achieving high-efficiency CZTSSe photovoltaic devices. At present, the Sn-related composition and defect modifications at different selenization pressures remain unclear, which restrain the development of efficient kesterite solar cells. Herein, a facile yet effective strategy to accurately adjust the Sn content in CZTSSe films by simply optimizing the selenization pressure is demonstrated. Compared with the widely used atmospheric pressure, it is unveiled that the appropriate negative pressure (0.7 atm) can tailor the optimal Sn content in the absorber layer, influencing both the Sn-related defects and the microstructures. In contrast, a lower (0.4 atm) and a higher (1.3 atm) selenization pressure results in undesirable deep Cu Sn defects and a Sn(S,Se) 2 secondary phase, respectively. A champion device fabricated at this optimal selenization pressure (0.7 atm) exhibits a power conversion efficiency of 11.32% with a V OC of 0.496 V. This study paves the path toward highly efficient kesterite solar cells by tailoring the composition-dependent defects.
研究领域:
材料科学
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太阳能电池技术
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DOI
高影响因子
Science Bulletin
·
2024
·
IF 18.8
Hailiang Wang,Qixian Zhang,Zedong Lin,Huicong Liu,Xiaozhen Wei,Yongfa Song,Chunyu Lv,Weiping Li,Liqun Zhu,Kexiang Wang,Zhenhua Cui,Lan Wang,Changqing Lin,Penggang Yin,Tinglu Song,Yang Bai,Qi Chen,Shihe Yang,Haining Chen
Defects formed at the surface, buried interface and grain boundaries (GB) of CsPbI 3 perovskite films considerably limit photovoltaic performance. Such defects could be passivated effectively by the most prevalent post modification strategy without compromising the photoelectric properties of perovskite films, but it is still a great challenge to make this strategy comprehensive to different defects spatially distributed throughout the films. Herein, a spatially selective defect management (SSDM) strategy is developed to roundly passivate various defects at different locations within the perovskite film by a facile one-step treatment procedure using a piperazine-1,4-diium tetrafluoroborate (PZD(BF 4 ) 2 ) solution. The small-size PZD 2+ cations could penetrate into the film interior and even make it all the way to the buried interface of CsPbI 3 perovskite films, while the BF 4 − anions, with largely different properties from I − anions, mainly anchor on the film surface. Consequently, virtually all the defects at the surface, buried interface and grain boundaries of CsPbI 3 perovskite films are effectively healed, leading to significantly improved film quality, enhanced phase stability, optimized energy level alignment and promoted carrier transport. With these films, the fabricated CsPbI 3 PSCs based on carbon electrode (C-PSCs) achieve an efficiency of 18.27%, which is among the highest-reported values for inorganic C-PSCs, and stability of 500 h at 85 °C with 65% efficiency maintenance.
研究领域:
材料科学
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能源技术
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光伏器件
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DOI
PubMed
高影响因子
Sustainable Energy & Fuels
·
2020
·Vol. 4
·期 4
·1674-1680
·
IF 5.503
Yingchen Yang,Zirui Lou,Weisheng Lei,Yichen Wang,Rong Liang,Chao Qin,Liping Zhu
Perovskite SrNbO2N particles were directly synthesized using a one-step thermal nitridation method with chloride flux and subsequently annealed under an inert Ar flow. By suitable adjustment of the flux synthesis parameters, including the nitridation temperature and the composition of the molten salt, preferable experimental conditions were found to suppress the formation of surface Nb defects and obtain samples with high crystallinity. The different SrNbO2N photoanodes were fabricated using the electrophoretic deposition (EPD) method followed by necking treatment. The SrNbO2N photoanode prepared using the optimum experimental conditions (nitridation temperature: 850 °C, a molar ratio of flux SrCl2 : KCl = 2 : 1) exhibited the highest photocurrent density of 2.0 mA cm−2 at 1.23 VRHE under simulated sunlight (AM 1.5G 100 mW cm−2) in a 1 M NaOH electrolyte. In comparison, the other highly defective SrNbO2N photoanodes demonstrated an unsatisfactory water oxidation performance, which demonstrates the necessity to reduce the destructive effect of defects in order to achieve a higher photocurrent density.
研究领域:
材料科学
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光电化学
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能源材料
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表面科学
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DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
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2024
·
IF 18.5
Jiaqi Zhang,Jianan Wang,Qishen Zhou,He Zhu,Yongyan Pan,Chenyang Shi,Sanwan Liu,Zheng Zhou,Huande Sun,Yong Cai,Rui Chen,Fumeng Ren,Zhengjing Zhao,Zihe Cai,Xiaojun Qin,Zhiguo Zhao,Zhichun Yang,Zonghao Liu,Wei Chen
All-perovskite tandem solar cells (TSCs) hold a great promise to break the Shockley-Queisser (S-Q) efficiency limit of single-junction solar cells. However, the inferior performance of the tin-lead (Sn–Pb) mixed perovskites based narrow-bandgap bottom subcells largely limits the development of all-perovskite TSCs due to the serious defects assisted non-radiative charge recombination loss, especially at the perovskite/electron charge transport layer (ETL) interface. Herein, a dual-source defect managing strategy is demonstrated to modify the top surface of Sn–Pb mixed perovskites. Specifically, ethylenediammonium diiodide (EDAI 2 ) and (3-mercaptopropyl) trimethoxysilane (MPTS) are simultaneously introduced to passivate the organic cations and metal cations related defects, respectively. The strong interactions between the passivators and Sn–Pb perovskite result in effectively reduced non-radiative carrier recombination, obviously suppressed Sn 2+ oxidation and accelerated carrier transportation at the perovskite/ETL interface. Ultimately, a champion efficiency of 22.7% for single-junction Sn–Pb solar cells and an impressive efficiency of 28.26% for the all-perovskite TSCs are achieved based on the dual-source defect managing strategy.
研究领域:
材料科学
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能源科学
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光伏技术
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产品关联
DOI
高影响因子
ENERGY & FUELS
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2022
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IF 4.654
Shuowen Wang,Yunfeng Bao,Yu Qi,Hai Zou,Shiwen Du,Xueshang Xin,Nengcong Yang,Chun Yang,Qing-lun Wang,Fuxiang Zhang
With a superior light-response ability and a high dielectric constant, the perovskite oxynitride SrNbO2N was expected to be an efficient photocatalyst for solar water splitting. However, a high defect density that formed during its preparation process had inhibited its charge separation and decreased the photocatalytic activity. In this work, SrNbO2N was modified through a high concentration doping of Zn2+ at the B site to inhibit its defect formation and promote its photocatalytic oxygen evolution performance. The defect formation in Sr(Nb2/3Zn1/3)O3–xNy (SNZON) is inhibited due to the sacrificial reduction of zinc ions during the nitridation process. Benefiting from the successful inhibition of defect formation and the promoted surface hydrophobicity, a remarkably promoted water oxidation activity was achieved on the as-obtained SNZON photocatalyst and the apparent quantum efficiency at 420 ± 10 nm reaches about 2.4%. This work may endow a new solution toward the preparation of low-defect oxynitride semiconductors with enhanced solar to chemical energy conversion efficiency.
研究领域:
材料科学
·
光催化
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太阳能转换
·
半导体物理
✓ 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）