JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2015
·Vol. 20
·期 1
·29-36
·
IF 2.446
Meng Ling,Liu Yingru,Zhang Jingbo,Bai Shouli,Luo Ruixian,Chen Aifan,Lin Yuan
A novel two-phase method was employed to directly deposit PbS quantum dots (QDs) on nanocrystalline SnO 2 thin films. In the two-phase method, the nanocrystalline SnO 2 thin film with adsorption of Pb 2+ ions was placed in an aqueous solution, and S 2− ions were dissolved in an oil solution. As two solutions were contacted, S 2− ions prefer to transfer to the aqueous solution and diffuse to the thin film surface with the adsorbed Pb 2+ ions to homogeneously form monodispersed PbS QDs on the nanocrystalline thin film. The homogeneous monodispersed QDs-sensitized thin film was used as a photoelectrode to fabricate QDs-sensitized solar cell. The loaded amount of PbS QDs and the thickness of ZnS passivation layer were optimized to obtain the highest light-to-electric conversion efficiency of 1.01 % under the simulated AM 1.5 illumination, which is increased by 61 % compared with that of the PbS QDs-sensitized solar cell employing the successive ionic layer adsorption and reaction (SILAR). The solar cell with homogeneous sensitization of QDs generates a photocurrent density of 11.09 mA·cm −2 , which is 2.4 times higher than that of the unhomogeneous one prepared by SILAR. The conversion efficiency enhancement mechanism due to the two-phase method was discussed in detail through the measurements of intensity-modulated photovoltage spectrum and electrochemical impedance spectroscopy.
研究领域:
材料科学
·
光电化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2020
·Vol. 14
·期 3
·628-634
·
IF 8.183
Zhang Xinsu,Chen Yujuan,Lian Linyuan,Zhang Zizhen,Liu Yixuan,Song Li,Geng Chong,Zhang Jianbing,Xu Shu
Infrared lead chalcogenide quantum dots (QDs) suffer fast degradation due to the easy oxidation of surface chalcogen atoms. Here, we report a trioctylphosphine-mediated surface passivation method to improve the air stability of PbS QDs. Surface mechanism study reveals an in situ surface reaction, which leads to site-selective passivation of surface S atoms with lead mono-carboxylate. The surface capping motif sufficiently protects PbS QDs from oxygen and improves their stability as well as quantum efficiency regardless of the QD size and original ligands on surface cations. The modified PbS QDs display no obvious fluorescence quenching and surface oxidization after 30 days of air exposure. The robust surface capping also provides high compatibility of PbS QDs with polymers for optoelectronic device fabrication. The near-infrared LEDs based on the modified PbS QDs display a slight degradation of only 1.47% from the maximum intensity after continuous operation in air for 250 hours (lifetime > 10,000 h) at 0.5 W/cm 2 power density, indicating the surface passivation route is promising strategy for promoting practical optoelectronic application of PbS QDs.
研究领域:
材料科学
·
光电技术
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 19
·195502
·
IF 3.874
Zhenzhen Ma,Jiahui Li,Yating Zhang,Hongliang Zhao,Qingyan Li,Chengqi Ma,Jianquan Yao
With extremely high optical absorption coefficient in infrared regime, lead sulfide (PbS) quantum dots (QDs)-based photodetectors are promising for diverse applications. In recent years, synthesis of materials has made great progress, but the problem of low sensitivity of quantum dots photodetector still unresolved. In this work, the introduction of a tunneling organic layer effectively address this problem. The dark current is decreased by the appropriate thickness of polymethyl methacrylate (PMMA) barrier layer by suppressing the spontaneous migration of ions, and the photogenerated carriers are little effected, thereby the responsivity of the device is improved. As a result, the device exhibits a high responsivity of 3.73 × 105 mA W−1 and a giant specific detectivity of 4.01 × 1013 Jones at a low voltage of −1 V under 1064 nm illumination. In the self-powered mode, the responsivity reaches a value of 157.6 mA W−1, and the detectivity up to 5.9 × 1011 Jones. The performance of the photodetectors is obviously better than most of the reported QDs photodetectors. The design of this device structure provides a new solution to the problem of low sensitivity and high leakage current of quantum dots based infrared photodetectors.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF RAMAN SPECTROSCOPY
·
2019
·Vol. 50
·期 10
·1445-1451
·
IF 2.809
Aili Liu,Huile Jin,Jun Li,Liyun Chen,Haoyuan Zheng,Xinnan Mao,Dajie Lin,Jichang Wang,Shun Wang,Weizhong Jiang
A microwave- and ultrasound-assisted reduction and assembly of lead dimethyldithiocarbamate (Pb (DMDC) 2 ) led to the formation of rod-like Pb (DMDC) 2 embedded with PbS quantum dots (QDs). Transmission electron microscopy measurements show the presence of numerous isolated PbS QDs on the Pb (DMDC) 2 microrod surface, which may potentially act as hot spots for enhanced Raman spectroscopy. A case study using mercaptopyridine as the analyte demonstrates that the rod-like hybrids have outstanding performance as a surface-enhanced Raman scattering (SERS) substrate, comparable with that of Au nanorods. The excellent SERS performance of the as-fabricated PbS QDs/Pb (DMDC) 2 hybrids may be attributed to the unique dispersion of PbS QDs as well as the intimate contacts between PbS QDs and Pb (DMDC) 2 . This study therefore presents a new approach for the development of low-cost and highly efficient semiconductor-based SERS substrates.
研究领域:
材料科学
·
光谱学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Haixia Xie,Cong Zhang,Jie Xu,Yong Pan,Xingtian Yin
PbS quantum dots have demonstrated potential as cost-effective materials for near-infrared photodetectors. Nevertheless, the performance of single-layer PbS quantum dot photodetectors remains unsatisfactory due to the low carrier mobility and high defect state concentration of colloidal quantum dot thin films. In this article, PbS quantum dot films are employed as the sensitizing layers for a-IGZO-based field-effect transistors (FET), which are able to achieve a low dark current and relatively high photocurrent simultaneously when working in the Poole–Frenkel emission region. The as prepared device shows a high responsivity of 25.89 A/W and detectivity of 2.46 × 1012 Jones, but very slow response speed with a decay time of 554 ms, which should be attributed to the high trap density in the PbS quantum dots film. Thus, we proposed a rapid annealing oxidation process to passivate the defects. As a result, after annealing in air at 100 °C for 10 min, the response speed of the device is significantly improved, and the decay time is as short as 2.5 ms, only at the expense of some responsivity and selectivity loss. However, further increasing the annealing temperature leads to excessive photocurrent loss and even affects the response speed improvement.
研究领域:
材料科学
·
电子工程
·
光电器件
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2019
·
IF 0
Panpan Wang,Ling Cao,Yu Chen,Ying Wu,Junwei Di
A novel kind of hydrogen peroxide (H2O2) photoelectrochemical (PEC) sensor was constructed based on Co3O4 and PbS nanomaterial modified indium tin oxide (ITO) photoelectrode. The Co3O4 nanoparticles, as mimic enzyme of catalase (CAT), can catalyze H2O2 to generate oxygen (O2) in suit. Then the electron acceptor of O2 enhances the cathodic photocurrent of the photoelectrode. The PEC sensor exhibited high sensitivity because of the formation of p–p type heterostructure between PbS and Co3O4 semiconductors. The photocurrent enhancement can be used to detect concentration of H2O2. The calibration plot was linear in the range from 5 to 250 μM, and the detection limit was estimated to be 1.2 μM. The results demonstrated the possibility of nanozyme application in PEC biosensors and the substitution of Co3O4 nanozyme for the natural enzyme.
研究领域:
生物传感技术
·
纳米材料科学
·
分析化学
✓ 已验证
产品关联
DOI
RSC Advances
·
2019
·Vol. 9
·期 27
·15307-15313
·
IF 3.049
Ling Cao,Panpan Wang,Li Chen,Ying Wu,Junwei Di
This work reports the first construction of the ternary layers of ITO/PbS/SiO2/AuNPs nanostructure for development of photoelectrochemical (PEC) glucose sensor. Herein, the thioglycolic acid-capped PbS quantum dots was employed as a PEC active probe, which is very sensitive to oxygen. The small gold nanoparticles (AuNPs) were act as nanozyme (mimic enzyme of glucose oxidase) to catalytically oxidize glucose in the presence of oxygen, meanwhile consumed oxygen and then resulted in the decrease of cathodic photocurrent. The insertion layer of SiO2 nanoparticles between PbS and AuNPs could reduce efficiently the base current due to its low electroconductivity, which improved the detection limit. The proposed PEC sensor exhibited high sensitivity and gold selectivity towards glucose. The linear response of glucose concentrations ranged from 1.0 μM to 1.0 mM with detection limit of 0.46 μM (S/N = 3). The results suggest the potential of design and development of numerous nanozyme-based PEC biosensors with the advantage of the simplicity, stability, and efficiency.
研究领域:
生物传感技术
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2021
·
IF 3.512
Qian Wang,Wen-Qi Chen,Xing-Yu Liu,Yi Liu,Feng-Lei Jiang
Near-infrared (NIR)-emitting PbS quantum dots (QDs) are endowed with good stability, high quantum yield, and long lifetime in the body, so they are promising agents in biological imaging. They quickly form the so-called “protein corona” through nonspecific adsorption with proteins in biological fluids once upon exposure to the biological system. Here, PbS QDs and human serum albumin (HSA) were selected as the model system. Fluorescence quenching spectroscopic studies indicated a static quenching process caused by the addition of PbS QDs, which was corroborated by the UV–vis absorption spectroscopy and fluorescence lifetime. Thermodynamic parameters were obtained by the fluorescence quenching method. The enthalpy change and entropy change were well correlated with the “enthalpy–entropy compensation” (EEC) equation summarized in this work. The slope (α = 1.08) and the intercept (TΔS0 = 34.44 kJ mol–1) indicated that the interaction resembled a protein–protein association. The both negative signs of enthalpy change and entropy change were elucidated by a proposed “two-step association–interaction” (TSAI) model. Agarose gel electrophoresis (AGE) and dynamic light scattering (DLS) showed that the binding ratio was roughly 2:1 (HSA/QDs), resembling sandwich-like structures. Furthermore, the secondary structure of HSA depended on the concentration of added QDs and the incubation time. The results preliminarily uncovered the physicochemical properties of QDs in the presence of proteins and elucidated the role of time evolution. These will inspire us to make the fluorescent QDs more biocompatible and use them in a proper way.
研究领域:
生物化学
·
纳米医学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 27
·15149-15157
·
IF 2.936
Wenhui Gao,Guangmei Zhai,Caifeng Zhang,Zhimeng Shao,Lulu Zheng,Yong Zhang,Yongzhen Yang,Xuemin Li,Xuguang Liu,Bingshe Xu
An initial improvement in performance of PbS quantum dot solar cells composed of one thick layer of PbS quantum dots (QDs) treated with tetrabutylammonium iodide (PbS–TBAI) and one thin layer of PbS QDs capped with 1,2-ethanedithiol (PbS–EDT) over short-term air exposure is widely observed. However, the underlying mechanisms still remain elusive. In the work, we sought to understand the mechanisms as well as their physicochemical origins using a combination of X-ray photoelectron spectroscopy (XPS) and various electronic measurements. It is found that the PbS–TBAI film plays a dominant role in the initial device performance improvement compared with the PbS–EDT film. The PbS–TBAI film is compensation doped upon short-term air exposure (one to three days) owing to the increase of Pb–O and/or Pb–OH species, enabling its energy band to align better with the electron transport layer for more efficient charge extraction. Moreover, it is demonstrated that the short-term air exposure is capable of reducing defects in the devices and improving the diode quality, resulting in an initial increase in device performance. This work contributes to the fundamental understanding of the surface chemistry changes of PbS quantum dots treated by different ligands over air-exposure and the role of surface chemistry of quantum dots in optimizing their photovoltaic performance.
研究领域:
材料科学
·
光伏技术
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers of Optoelectronics
·
2024
·Vol. 17
·期 1
·1-7
·
IF 4.1
Li Zha,Li Wancai,Li Dehui,Tang Wei,Liang Huageng,Song Huaibing,Chen Chao,Gao Liang,Tang Jiang
Chiral inorganic semiconductors with high dissymmetric factor are highly desirable, but it is generally difficult to induce chiral structure in inorganic semiconductors because of their structure rigidity and symmetry. In this study, we introduced chiral ZnO film as hard template to transfer chirality to CsPbBr 3 film and PbS quantum dots (QDs) for circularly polarized light (CPL) emission and detection, respectively. The prepared CsPbBr 3 /ZnO thin film exhibited CPL emission at 520 nm and the PbS QDs/ZnO film realized CPL detection at 780 nm, featuring high dissymmetric factor up to around 0.4. The electron transition based mechanism is responsible for chirality transfer. Graphical Abstract
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small
·
2021
·Vol. 18
·期 1
·2105495
·
IF 13.281
Mingyu Li,Shiwu Chen,Xinzhao Zhao,Kao Xiong,Bo Wang,Usman Ali Shah,Liang Gao,Xinzheng Lan,Jianbing Zhang,Hsien-Yi Hsu,Jiang Tang,Haisheng Song
Infrared solar cells (IRSCs) can supplement silicon or perovskite SCs to broaden the utilization of the solar spectrum. As an ideal infrared photovoltaic material, PbS colloidal quantum dots (CQDs) with tunable bandgaps can make good use of solar energy, especially the infrared region. However, as the QD size increases, the energy level shrinking and surface facet evolution makes us reconsider the matching charge extraction contacts and the QD passivation strategy. Herein, different to the traditional sol-gel ZnO layer, energy-level aligned ZnO thin film from a magnetron sputtering method is adopted for electron extraction. In addition, a modified hybrid ligand recipe is developed for the facet passivation of large size QDs. As a result, the champion IRSC delivers an open circuit voltage of 0.49 V and a power conversion efficiency (PCE) of 10.47% under AM1.5 full-spectrum illumination, and the certified PCE is over 10%. Especially the 1100 nm filtered efficiency achieves 1.23%. The obtained devices also show high storage stability. The present matched electron extraction and QD passivation strategies are expected to highly booster the IR conversion yield and promote the fast development of new conception QD optoelectronics.
研究领域:
材料科学
·
光伏技术
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Xiaokun Yang,Ji Yang,Muhammad Irfan Ullah,Yong Xia,Guijie Liang,Song Wang,Jianbing Zhang,Hsien-Yi Hsu,Haisheng Song,Jiang Tang
Solution-processed semiconductors have opened promising avenues for next-generation semiconductor and optoelectronic industries. Colloidal quantum dots (QDs) as one of the most typical materials are widely utilized for the design and development of light-emitting diodes, photodetectors, and solar cells. Recently, an emerging process of PbS QD ink has been employed to attain world record power conversion efficiency by surface passivation using a PbI2 ligand to form PbI2–PbS and the process optimization in the field of photovoltaics. However, the bonding and debonding of the ligands on the surface of PbS QDs are dynamic reversible processes in an ink environment. The uncoordinated Pb2+ defects induced by unbonded PbS QDs serve as the recombination sites. Thus, the present ink process leaves much room for the enhancement by surface passivation of PbS QDs. Herein, we devise an efficient strategy with a supplementary phenethylammonium iodide (PEAI) ligand for the formation of the PEAI–PbS interface in PbS QD ink-processed solar cells. This newly developed method can not only improve the passivation on the QD surface by iodine ions but also simultaneously enhance the carrier collection efficiency by a graded energy alignment between PbI2–PbS and PEAI–PbS layers. The corresponding power conversion efficiency of the optimized device has significantly increased by approximately 20% more than the control device. As a result, such a robust and efficient method regarded as a strategic candidate can overcome the bottleneck of imperfect passivation caused by a large specific surface area and loose bonding ligands, eventually promoting the industrial application of QDs.
研究领域:
材料科学
·
光伏技术
·
纳米科技
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）