Low loading is one of the bottlenecks limiting the performance of quantum dot sensitized solar cells (QDSCs). Although previous QD secondary deposition relying on electrostatic interaction can improve QD loading, due to the introduction of new recombination centers, it is not capable of enhancing the photovoltage and fill factor. Herein, without the introduction of new recombination centers, a convenient QD secondary deposition approach is developed by creating new adsorption sites via the formation of a metal oxyhydroxide layer around QD presensitized photoanodes. MgCl2 solution treated Zn–Cu–In–S–Se (ZCISSe) QD sensitized TiO2 film electrodes have been chosen as a model device to investigate this secondary deposition approach. The experimental results demonstrate that additional 38% of the QDs are immobilized on the photoanode as a single layer. Due to the increased QD loading and concomitant enhanced light-harvesting capacity and reduced charge recombination, not only photocurrent but also photovoltage and fill factor have been remarkably enhanced. The average PCE of resulted ZCISSe QDSCs is boosted to 15.31% (J sc = 26.52 mA cm–2, V oc = 0.802 V, FF = 0.720), from the original 13.54% (J sc = 24.23 mA cm–2, V oc = 0.789 V, FF = 0.708). Furthermore, a new certified PCE record of 15.20% has been obtained for liquid-junction QDSCs.

Colloidal nanocrystals (NCs) are intriguing building blocks for assembling various functional thin films and devices. The electronic, optoelectronic, and thermoelectric applications of solution-processed, inorganic ligand (IL)-capped colloidal NCs are especially promising as the performance of related devices can substantially outperform their organic ligand-capped counterparts. This in turn highlights the significance of preparing IL-capped NC dispersions. The replacement of initial bulky and insulating ligands capped on NCs with short and conductive inorganic ones is a critical step in solution-phase ligand exchange for preparing IL-capped NCs. Solution-phase ligand exchange is extremely appealing due to the highly concentrated NC inks with completed ligand exchange and homogeneous ligand coverage on the NC surface. In this review, the state-of-the-art of IL-capped NCs derived from solution-phase inorganic ligand exchange (SPILE) reactions are comprehensively reviewed. First, a general overview of the development and recent advancements of the synthesis of IL-capped colloidal NCs, mechanisms of SPILE, elementary reaction principles, surface chemistry, and advanced characterizations is provided. Second, a series of important factors in the SPILE process are offered, followed by an illustration of how properties of NC dispersions evolve after ILE. Third, surface modifications of perovskite NCs with use of inorganic reagents are overviewed. They are necessary because perovskite NCs cannot withstand polar solvents or undergo SPILE due to their soft ionic nature. Fourth, an overview of the research progresses in utilizing IL-capped NCs for a wide range of applications is presented, including NC synthesis, NC solid and film fabrication techniques, field effect transistors, photodetectors, photovoltaic devices, thermoelectric, and photoelectrocatalytic materials. Finally, the review concludes by outlining the remaining challenges in this field and proposing promising directions to further promote the development of IL-capped NCs in practical application in the future.

Benefiting from the suppressed charge recombination occurring at the photoanode/electrolyte interfaces with the introduction of TEOS additive in the polysulfide electrolyte, a remarkable PCE of over 12% was obtained for ZCISe QDSCs.

Unambiguously direct adsorption (DA) of initial oil-soluble quantum dots (QDs) on TiO film electrode is a convenient and simple approach in the construction of quantum dot sensitized solar cells (QDSCs). Regrettably, low QD loading amount and poor reproducibility shadow the advantages of DA route and constrain its practical application. Herein, the influence of experimental variables in DA process on QD loading amount as well as on the photovoltaic performance of the resultant QDSCs was investigated and optimized systematically, including the choice of solvent, purification of QDs, and sensitization time, as well as QD concentration. Experimental results demonstrated that it is essential to choose appropriate solvent as well as control purification cycles of original QD suspensions so as to realize satisfactory QD loading amount and ensure the high reproducibility. In addition, DA mode renders efficient electron injection from QD to TiO, yet low QD loading amount and adverse QD agglomeration in comparison with the well-developed capping ligand induced self-assembly (CLIS) deposition approach. Mg treatment on TiO photoanodes can promote the QD loading amount in DA mode. The optimized QDSCs based on DA mode exhibited efficiencies of 6.90% and 9.02% for CdSe and Zn-Cu-In-Se QDSCs, respectively, which were comparable to the best results based on CLIS mode (6.88% and 9.56%, respectively).

Replacing initial long chain organic ligands by small, stable, and conductive inorganic ligands (ILs) via inorganic ligand exchange reaction (ILER) opens up new opportunities for the functionalization and application of colloidal nanocrystals (NCs). Although IL functionalized NCs have been successfully obtained via ILER for most ILs, some common anions, including F–, NO3 –, SO4 2–, and ClO4 – with extremely weak coordination ability, are hardly explored. Herein, we demonstrate for the first time the access of these IL capped NCs via ILER by using H+ as the electrophile reagent, which efficiently and irreversibly strips off the original organic ligands first. A long-term colloidal stability can be realized for these anion capped NCs via the replacement of H+ by other suitable monovalent counterions. It is believed that the successful capping with these hard ILs for soft NCs such as CdSe will not only promote the development of IL exchange theory and mechanism but also significantly enrich the toolbox of colloidal NCs and provide great opportunities in the design and construction of new NC-based devices.

Cholangiocarcinoma (CCA) is a rare cancer biliary tract malignancy which accounts for less than 3% of all gastrointestinal cancers diagnosed worldwide (1). The incidence of CAA is highest in Thailand, China, and other Asian populations, but is lowest in the western world, presumably reflecting differences in the exposure of genetic and other risk factors (2). Anatomically, CCA can be divided into intrahepatic or extrahepatic subtypes choosing second-order bile ducts as the point of separation (3). The majority of CCA are extrahepatic cholangiocarcinoma (eCCA), whereas Summary Immunotherapy might be an effective treatment in extrahepatic cholangiocarcinoma (eCCA), a tumor with extremely limited therapeutic options. Our study is to characterize the programmed death ligand-1 (PD-L1) protein expression and cancer microenvironment profiles in surgically resected eCCA samples. PD-L1 positivity was observed on tumor cells (32.3%) as well as on tumor-associated macrophages (74.2%). PD-L1 expression by eCCA correlated significantly with immune parameters such as intra-tumoral CD3+ tumor infiltrating lymphocytes (TILs) density (P = 0.002), intra-tumoral CD8+ TILs density (P < 0.001), and the expression pattern of human leukocyte antigen (HLA) class I (P < 0.001). Immunofluorescence showed that PD-L1 positive tumor cells were adjacent to PD-1 positive cells and the stroma covered with interferon-γ. Correlation with clinicopathological parameters and survival analyses revealed that PD-L1 positivity in eCCA was related to the absence of venous invasion (P = 0.030), improved overall survival (P = 0.020) and progressionfree survival (P = 0.011). HLA class I molecules defect, which is an important mechanism of immune evasion, was frequently observed in eCCA (50.0%) and was associated with a decreased number of intra-tumoral CD8+ TIL density (P = 0.028). Additionally, the presence of unusually high numbers of tumor-associated macrophages (TAMs) subsets M2 in most of eCCA (74.2%) was noted. Our study indicated that PD-L1 expression in association with intra-tumoral TILs infiltration and HLA class I expression in 32.3% of the eCCA reflects an active immune microenvironment potentially responsive to PD-1/PD-L1 inhibitors. In addition, the combination of macrophage-targeting agents may provide therapeutic synergy for future immunotherapy.

Reactive oxygen species (ROS) are unstable reactive molecules that are toxic to cells. Regulation of ROS homeostasis is crucial to protect cells from dysfunction, senescence and death. In plant leaves, ROS are mainly generated from chloroplasts and are tightly temporally restricted by the circadian clock. However, little is known about how ROS homeostasis is regulated in non-photosynthetic organs, such as petals. Here, we showed that H2O2 levels exhibit typical circadian rhythmicity in rose (Rosa hybrida) petals, consistent with the measured respiratory rate. RNA-seq and functional screening identified a B-box gene, RhBBX28, whose expression was associated with H2O2 rhythms. Silencing RhBBX28 accelerated flower senescence and promoted H2O2 accumulation at night in petals, while overexpression of RhBBX28 had the opposite effects. RhBBX28 influenced the expression of various genes related to respiratory metabolism, including the TCA cycle and glycolysis, and directly repressed the expression of SUCCINATE DEHYDROGENASE 1, which plays a central role in mitochondrial ROS homeostasis. We also found that PHYTOCHROME INTERACTING FACTOR8 (RhPIF8) could activate RhBBX28 expression to control H2O2 levels in petals and thus flower senescence. Our results indicate that the circadian- controlled RhPIF8-RhBBX28 module is a critical player that controls flower senescence by governing mitochondrial ROS homeostasis in rose.

The balance between band structure, composition, and defect is essential for improving the optoelectronic properties of ternary and quaternary quantum dots and the corresponding photovoltaic performance. In this work, ascorbic acid (AA) as capping ligand is introduced into the reaction system to prepare green Zn–Cu–In–Se (ZCISe) quantum dots. Results show that the addition of AA can increase the Zn content while decrease the In content, resulting in enlarged band gap, high conduction band energy level, and suppressed charge recombination. When AA/Cu ratio is 1, the quantum dots possess the largest band gap of 1.49 eV and the assembled quantum dot-sensitized solar cells exhibit superior photovoltaic performance with ∼17% increment mainly contributed by the dramatically increased current density. The new record efficiencies of 10.44 and 13.85% are obtained from the ZCISe cells assembled with brass and titanium mesh-based counter electrodes, respectively.