Science Bulletin
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2024
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IF 18.8
Hang Zhou,Yingjie Sun,Miao Zhang,Yuheng Ni,Fenghua Zhang,Sang Young Jeong,Tianhuan Huang,Xiong Li,Han Young Woo,Jian Zhang,Wai–Yeung Wong,Xiaoling Ma,Fujun Zhang
The vertical phase distribution of active layers plays a vital role in balancing exciton dissociation and charge transport for achieving efficient polymer solar cells (PSCs). The layer–by–layer (LbL) PSCs are commonly prepared by using sequential spin–coating method from donor and acceptor solutions with distinct solvents and solvent additives. The enhanced exciton dissociation is expected in the LbL PSCs with efficient charge transport in the relatively neat donor or acceptor layers. In this work, a series of LbL all–polymer solar cells (APSCs) were fabricated with PM6 as donor and PY–DT as acceptor, and triplet material m –Ir(CPmPB) 3 is deliberately incorporated into PY–DT layer to prolong exciton lifetimes of active layers. The power conversion efficiency (PCE) of LbL APSCs is improved to 18.24% from 17.32% by incorporating 0.3 wt% m –Ir(CPmPB) 3 in PY–DT layer, benefiting from the simultaneously enhanced short–circuit current density ( J SC ) of 25.17 mA cm −2 and fill factor (FF) of 74.70%. The enhancement of PCE is attributed to the efficient energy transfer of m –Ir(CPmPB) 3 to PM6 and PY–DT, resulting in the prolonged exciton lifetime in the active layer and the increased exciton diffusion distance. The efficient energy transfer from m –Ir(CPmPB) 3 to PM6 and PY–DT layer can be confirmed by the increased photoluminescence (PL) intensity and the prolonged PL lifetime of PM6 and PY–DT in PM6 + m –Ir(CPmPB) 3 and PY–DT + m –Ir(CPmPB) 3 films. This study indicates that the triplet material as solid additive has great potential in fabricating efficient LbL APSCs by prolonging exciton lifetimes in active layers.
研究领域:
材料科学
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光物理学
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产品关联
DOI
PubMed
高影响因子
Advanced Optical Materials
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2024
·Vol. 12
·期 18
·2400141
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IF 8
Hongyu Yang,Jingzhou Li,Zhanpeng Wang,Yichi Zhong,Hanhuai Yang,Hongxing Dong,Long Zhang
Lead halide perovskite quantum dots (LHP QDs) emerge as versatile photonic sources in electroluminescence and laser devices. Their applications in optoelectronic devices are hindered by surface distortion and ligand stripping during the purification process. In addition, the device performance roll-off suffers from the ultrafast non-radiative Auger recombination (AR). To address these issues, herein, CsPbBr 3 QDs are prepared with sizes ranging from 6.5 to 9.2 nm and the universal surface repairing strategy is proved to efficiently increase the biexciton lifetime and quantum yield up to 1.4 and 3 times, respectively. The strategy provides a PbBr x rich surface and strong binding didodecyldimethylammonium bromide (DDAB) ligands to achieve near-unity photoluminescence efficiency, which significantly improves their stability against anti-solvents and aging in ambient conditions. A single-mode laser device is realized by self-assembling the QDs into superlattice as optical microcavity, with low threshold of 9.45 µJ cm −2 , quality factor of 2187 and ultrafast lifetime of 3.22 ps. The superlattice laser is demonstrated as an optical encoder with large coding bandwidth of 0.133 THz. This work proposes new insight into the non-radiative AR process in these single-component CsPbBr 3 QDs, and will pave the way for optoelectronic devices working in intense conditions.
研究领域:
材料科学
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光学工程
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纳米技术
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DOI
高影响因子
SOLID STATE COMMUNICATIONS
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2023
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IF 2.1
Zhigang Li,Yuanjie Sun,Hongtao Zhao
Lead free double perovskite nanocrystals is an ideal alternate considering its nontoxic and stable property comparing with their counterpart lead halide perovskite NCs. A simple solution synthesis strategy was used to prepare lead-free double perovskite Cs 2 AgBiBr 6 nanocrystals (NCs) doped with Na ions , resulting in NCs with a monodisperse state, homogeneous morphology, and good crystallinity . By adjusting the amount of Na + doping, the band gap of the NCs was significantly increased from 2.57 eV to 3.00 eV. Furthermore, the relatively low value of photoluminescence quantum yield (PLQY) in the original Cs 2 AgBiBr 6 NCs (∼0.5%) was increased to about 8.5% when doped with 60% Na + . Additionally, the exciton lifetime of the NCs was extended to 16.15 ns compared to the original 2 ns. As a result, the doping of Na + significantly enhanced the PLQY of Cs 2 AgBiBr 6 NCs, indicating their potential value for use in optoelectronic devices .
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Optical Materials
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2025
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IF 7.2
Junfeng Wang,Qing Chen,Fei Huang,Jie Meng,Jiawei Li,Zhenyun Lan,Qian Zheng,Shuyu Tian,Kaibo Zheng,Tönu Pullerits,Jianjun Tian
Epitaxial shell is vital for enhancing the optoelectronic performance of semiconductor quantum dots (QDs), especially for the wide bandgap blue QDs, yet the shell crystal structure's impact on thermal stability and photophysical behavior remains unexplored. It is reported that the ligand-directed synthesis of ZnS shells with zinc blende (ZB) or wurtzite (WZ) structure on blue WZ CdZnS cores, where sulfur precursor (Trioctylphosphine-S/octanethiol) dictates crystal phase through their thermal stability and coordination effects. WZ ZnS exhibits a lower Cd 2 ⁺ diffusion barrier than ZB ZnS due to reduced cation density in octahedral vacancies, lowering electrostatic repulsion. Consequently, ZB-shell QDs maintain sharp core-shell boundary and energy band alignment, improving anti-thermal quenching and structural stability: fluorescence decreased by only 8% versus 17% for WZ-shell QDs with increasing temperature from 200 to 300 K, and retained 81% fluorescence intensity (vs. 36%) after 15 days at 100 °C. The rigid ZB lattice also weakens exciton-phonon coupling (simulated γLO = 39 meV vs. 67 meV for WZ). Conversely, WZ-shell QDs form alloyed interfaces enabling smooth energy band alignment, enhancing carrier delocalization. This suppresses Auger recombination, yielding a biexciton lifetime of 126 ps—nearly double that of ZB-shell QDs (69 ps)—and slower decay kinetics (τ av = 16.7 ns vs. 55 ns).
研究领域:
材料科学
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纳米科技
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半导体物理
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光电子学
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胶体化学
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凝聚态物理
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产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
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2023
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IF 8.6
Jieyu Zhang,Jingjing Min,Binghan Li,Wenxing Yang,Zaiping Zeng,Dianyi Liu,Botao Ji
Environmentally friendly Ag2S nanocrystals (NCs) show potential applications as light-absorbing semiconductors for thin-film photovoltaics or biological taggants. However, thiol ligands are generally involved during the synthesis of Ag2S NCs to maintain colloidal stability, hindering postexchange of these crystal-bound thiolate ligands. Here, using common non-thiol ligands (oleic acid and oleylamine), we develop a general strategy of surface heterovalent-metal (Bi3+, Ga3+, In3+, Sb3+, and Zn2+) decoration to synthesize colloidal cation-rich Ag2S NCs achieving a high photoluminescence quantum yield up to 22% at ∼1230 nm. Density functional theory calculations reveal the heterovalent-metal cations exhibit stronger orbital coupling to the ligands than Ag atoms, and thus stronger binding affinity, resulting in reduced dynamic surface ligands to produce compact cation-rich Ag2S NCs with high solubility in nonpolar solvents. We further show that surface-decorated Bi atoms can accumulate the electron charge density, leading to surface-related band-edge emissions with increased electron–hole separation and prolonged exciton lifetimes of the Bi-decorated Ag2S NCs, which are desirable for many optoelectronic conversion applications. Using a 40 nm-thick light-absorbing layer of Bi-decorated Ag2S NCs, the optimized solar cells show a short-circuit current density of 18.6 mA cm–2 and a power conversion efficiency of over 4%.
研究领域:
材料科学
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纳米技术
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光伏技术
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光电技术
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）