Sufficient loading of presynthesized quantum dots (QDs) on mesoporous TiO 2 electrodes is the prerequisite for the fabrication of high-performance QD-sensitized solar cells (QDSCs).Here, we provide a general approach for increasing QD loading on mesoporous TiO 2 films by surface engineering. It was found that the zeta potential of presensitized TiO 2 can be effectively adjusted by surfactant treatment, on the basis of which additional QDs are successfully introduced onto photoanodes during secondary deposition. The strategy developed, that is, the secondary deposition incorporating surfactant treatment, makes it possible to load various QDs onto photoanodes regardless of the nature of QDs. In standard AM 1.5G sunlight, a certified efficiency of 10.26% for the QDSC with Cu 2 S/brass counter electrodes was achieved by the secondary deposition of Zn−Cu−In−Se QDs.

A facile method for synthesizing high-quality Cu–In–Se quantum dots (QDs) was developed by Al/Zn co-incorporation. Benefiting from the reduction of trap-state defects in QDs, the efficiency of solar cells basing prepared QDs is obviously improved.

Porous aromatic frameworks (PAFs) were first reported in 2009 and have quickly attracted much attention because of their exceptionally ultrahigh specific surface area (5800 m2·g–1). Uniquely, PAFs are constructed from carbon–carbon-bond-linked aromatic-based building units, which render PAFs extremely stable in various environments. At present, PAFs have been applied in many fields, such as adsorption, catalysis, ion exchange, electrochemistry, and so on. However, for such a unique material, its application in the biological fields is still rarely explored. Therefore, this Perspective introduces the reported application of PAFs in biological fields, for instance, diagnosis and treatment of diseases, artificial enzymes, drug delivery, and extraction of bioactive substances. Major challenges and opportunities for future research on PAFs in biology and biomedicine are identified in diagnostic platforms, novel drug carriers/antidotes, and novel artificial enzymes.

High-quality QDs play a crucial role in the fabrication of high-performance quantum dot-sensitized solar cells (QDSCs). Surface defects/traps of QDs commonly act as nonradiative carrier recombination centers and thereby deteriorate the power conversion efficiency of the fabricated QDSCs. Herein a protective ZnSe shell is grown on the surface of Al/Zn coincorporated Cu–In–Se QDs to form (Al/Zn)–Cu–In–Se/ZnSe (AZCISe/ZnSe) core/shell QDs, which are used as light harvesters to fabricate QDSCs. It is found that the PL intensity of AZCISe/ZnSe QDs is significantly improved as the ZnSe shell thickness increases, indicating that the ZnSe shell is beneficial to reduce the surface defects/traps of AZCISe QDs. Moreover, the ZnSe shell thickness can be tailored by controlling the cycles of injected Zn and Se precursors during the synthesis process. Furthermore, electrochemical impedance spectroscopy, open-circuit voltage decay, and time-resolved fluorescence spectroscopy analysis demonstrate that the ZnSe shell layer can effectively reduce the surface defect/trap density of the QDs, suppress the charge recombination at photoanode/electrolyte interfaces, and improve the photovoltaic performance of the constructed QDSCs. Benefiting from the surface engineering of QDs, the average power conversion efficiency increases from 10.15% for pristine AZCISe QDSCs to 10.53% for AZCISe/ZnSe core/shell QDSCs.

No abstract