The unstable PbSe quantum dot (QD) surface requires tedious and complicated synthetic protocols and renders them substantially underdeveloped compared to PbS QDs. Here, we describe a direct synthesis of PbSe QD inks at room temperature. In comparison to the conventional three-step synthesis, our strategy simplifies the fabrication process to one step and reduces the preparation cost by a factor of eight. A photovoltaic device based on these PbSe QD inks has achieved a photovoltaic conversion efficiency (PCE) of 10.38% with high device stability, which is one of the highest PCEs for all reported PbSe QD solar cells. More importantly, the obtained ink has demonstrated the best colloidal stability by far compared with all the reported lead chalcogenides (PbX) QD inks for photovoltaic application. This simple and low-cost synthesis will facilitate ink storage and transport and may ignite a new round of research efforts on the optoelectronic applications of PbSe QDs.

We present a living cationic polymerization of vinyl ethers utilizing electrophilic selenium reagents as initiators and pentacarbonylbromomanganese (Mn(CO)5Br) as the catalyst.

Ring-opening copolymerization (ROCOP) is an effective means to prepare functionalized polyester. In this work, a type of selenide-containing polyesters with controllable structure, molecular weight, and molecular weight distribution was successfully prepared by ROCOP of γ-selenobutyrolactone and epoxy compounds. The influence of the catalyst, solvent, and reaction temperature on the reaction efficiency was examined. Then, kinetic study was investigated under an optimized condition. The structure of the copolymers was carefully characterized by nuclear magnetic resonance (NMR), 1H NMR, 13C NMR, and 77Se NMR, Matrix-assisted laser-desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and size exclusion chromatography (SEC). The resulting polymers showed a linear structure with a sequence regulated backbone repeating unit of ester-selenide. On this basis, some typical epoxides were investigated to verify the scope of the polymerization system. Due to the “living”/controlled characteristics of this ROCOP, multiblock, amphiphilic, and stereotactic copolymers could be prepared with a pre-designed structure. As expected, the selenide-containing amphiphilic copolymer could self-assemble to micelles and showed an oxidative response.

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