All-inorganic perovskite cesium lead halide quantum dots (QDs) have been widely investigated as promising materials for optoelectronic application because of their outstanding photoluminescence (PL) properties and benefits from quantum effects. Although QDs with fullspectra visible emission have been synthesized for years, the PL quantum yield (PLQY) of pure blue-emitting QDs still stays at a low level, in contrast to their green-or redemitting counterparts. Herein, we obtained core−shell structured cubic CsPbBr 3 @amorphous CsPbBr x (A-CsPbBr x ) perovskite QDs via a facile hot injection method and centrifugation process. The core−shell structure QDs showed a record blue emission PLQY of 84%, which is much higher than that of blue-emitting cubic CsPbBr 3 QDs and CsPbBr x Cl 3−x QDs. Furthermore, a blue-emitting QDsassisted LED with bright pure blue emission was prepared and illustrated the core−shell QDs' promising prospect in optoelectrical application.

A fully automated spray-coated technology with ultrathin-film purification is exploited for the commercial large-scale solution-based processing of colloidal inorganic perovskite CsPbI 3 quantum dot (QD) films toward solar cells. This process is in the air outside the glove box. To further improve the performance of QD solar cells, the short-chain ligand of phenyltrimethylammonium bromide (PTABr) with a benzene group is introduced to partially substitute for the original long-chain ligands of the colloidal QD surface (namely PTABr-CsPbI 3 ). This process not only enhances the carrier charge mobility within the QD film due to shortening length between adjacent QDs, but also passivates the halide vacancy defects of QD by Br − from PTABr. The colloidal QD solar cells show a power conversion efficiency (PCE) of 11.2% with an open voltage of 1.11 V, a short current density of 14.4 mA cm −2 , and a fill factor of 0.70. Due to the hydrophobic surface chemistry of the PTABr-CsPbI 3 film, the solar cell can maintain 80% of the initial PCE in ambient conditions for one month without any encapsulation. Such a low-cost and efficient spraycoating technology also offers an avenue to the film fabrication of colloidal nanocrystals for electronic devices.with a large bandgap of 2.82 eV. [24,25] Many efforts have tried to partly replace I − with Br − to increase the stability of the black phase. [17,26,27] Unfortunately, the introduction of the bromine component enlarges the bandgap of the perovskite, correspondingly to harm the light-harvesting performance. The cubic structure of CsPbI 3 also can be stabilized by the colloidal quantum dot (QD) method, because the enlarging surface energy inhibits the phase transition. [28][29][30] In addition, on the basis of the multiple exciton generation effects, the narrow bandgap colloidal QDs will exceed the single-junction Shockley-Queisser solar efficiency limit to achieve higher theoretical efficiency. [31,32] Several efforts have built the devices with quite inspiring efficiency using the CsPbI 3 QD film as the active layer. [14,30,[33][34][35][36][37][38] However, the CsPbI 3 QDs are usually deposited to form the thin film by the spin-coating method. This method is an undesirable way to realize the scaled manufacture of the QD thin film because of the small deposition area. [39] To economize the cost of materials and realize scalable film deposition, the spray coating is emerging as a typical process for the fabrication of the thin films and has been used in the commercial paint coat technology. [32,39] However, the spray-coating process is hard to obtain high quality compact thin-film of colloidal QD due to long chain surface organic ligands of QD that weakens the adhesive force between QD and substrate. The surface ligands are obstructive to the formation of QD films and performance of the devices by hindering the charge transport. But the surface ligands are necessary to maintain monodisperse QDs and suppress their agglomeration. How to balance the surface ligands and the adhesive f...

Colloidal cesium lead iodide (CsPbI3) perovskite quantum dots (QDs) are promising materials for solar cells because of their suitable optical bandgap and the ease of solution-based processing into large-area films. Herein, we report a synthetic strategy to build up a colloidal CsPbI3/PbSe heterostructure, which not only improves the absorption of sunlight but also passivates the surface of perovskite QDs, which results in a lower trap density and prolonged exciton lifetimes. Moreover, the presence of the PbSe component modifies the electronic properties of the composite films, by changing the CsPbI3 QD film from n-type to more ambipolar behavior, thus helping to promote carrier separation and collection. These improvements result in high-performance CsPbI3/PbSe QD solar cells with a power conversion efficiency of 13.9% and improved storage stability against moisture, benefiting from the hydrophobic protective coating resulting from the presence of PbSe component.

All inorganic halide perovskites in the form of colloidal quantum dots (QDs) have come into people’s view as one of the potential materials for the high-efficiency solar cells; nevertheless, the high surface trap density and poor stability of QDs restrict the performance improvement and application. Here, we obtain colloidal inorganic perovskite CsPb1–x Zn x I3 QDs by the hot-injection synthesis process with the addition of ZnCl2. Synchrotron-based X-ray absorption fine structures demonstrate that the guest Zn2+ ions are doped into the CsPbI3 structure to improve the local ordering of the lattice of the perovskite, reducing the octahedral distortions. The increase of the Goldschmidt tolerance factor and the Pb–I bond energy also enhance the stability of the perovskite structure. Furthermore, the Cl– ions from ZnCl2 occupy the iodide vacancies of the perovskite to decrease the nonradiative recombination. The synergistic effect of doping and defect passivation makes for stable colloidal CsPb0.97Zn0.03I3 QDs with ultralow density of trap states. The champion solar cell based on the QDs shows a power conversion efficiency of 14.8% and a largely improved stability under ambient conditions.

Because of their attractive chemical and physical properties, graphitic nanomaterials and their derivatives have gained tremendous interest for applications in electronics, materials, and biomedical areas. However, few detailed studies have been performed to evaluate the potential cytotoxicity of these nanomaterials on living systems at the molecular level. In the present study, our group exploited the isobaric tagged relative and absolute quantification (iTRAQ)-coupled two-dimensional liquid chromatography-tandem mass spectrometry (2D LC-MS/MS) approach with the purpose of characterizing the cellular functions in response to these nanomaterials at the proteome level. Specifically, the human hepatoma HepG2 cells were selected as the in vitro model to study the potential cytotoxicity of oxidized single-walled carbon nanotubes (SWCNTs) and graphene oxide (GO) on the vital organ of liver. Overall, 30 differentially expressed proteins involved in metabolic pathway, redox regulation, cytoskeleton formation, and cell growth were identified. Based on the protein profile, we found oxidized SWCNTs induced oxidative stress and interfered with intracellular metabolic routes, protein synthesis, and cytoskeletal systems. Further functional assays confirmed that oxidized SWCNTs triggered elevated level of reactive oxygen species (ROS), perturbed the cell cycle, and resulted in a significant increase in the proportion of apoptotic cells. However, only moderate variation of protein levels for the cells treated with GO was observed and functional assays further confirmed that GO was less cytotoxic in comparison to oxidized SWCNTs. These finding suggested that GO was more biocompatible and could be a promising candidate for bio-related applications.