Solution processable small molecules have been widely applied for photovoltaic (PV) devices in recent years because they show strong absorption properties, and they can be easily purified and deposited onto flexible substrates at low cost. Introducing different donor and acceptor groups to construct donor-acceptor (D-A) structure small molecules has proved to be an efficient way to improve the properties of organic solar cells (OSCs). This review deals with the recent progress of solution processable D-A structure small molecules and discusses the key factors affecting the properties of OSCs based on D-A structure small molecules: sunlight absorption, charge transport and the energy level of the molecules. Then we give some suggestions for designing new solution processable D-A structure small molecules for high performance OSCs.

Four porous isostructural mixed-metal-organic frameworks (M'MOFs) have been synthesized and structurally characterized. The pores within these M'MOFs are systematically tuned by the interplay of both the metalloligands and organic ligands which have enabled us not only to direct their highly selective separation of chiral alcohols 1-phenylethanol (PEA), 2-butanol (BUT), and 2-pentanol (2-PEN) with the highest ee up to 82.4% but also to lead highly selective separation of achiral C(2)H(2)/C(2)H(4) separation. The potential application of these M'MOFs for the fixed bed pressure swing adsorption (PSA) separation of C(2)H(2)/C(2)H(4) has been further examined and compared by the transient breakthrough simulations in which the purity requirement of 40 ppm in the outlet gas can be readily fulfilled by the fixed bed M'MOF-4a adsorber at ambient conditions.

Organic cocrystals possess valuable properties owing to the synergistic effect of the individual components. However, the growth of molecular cocrystals is still in its primary stage. Here we develop a microspacing in-air sublimation method to grow organic cocrystals, and furthermore to realize morphology control on them, which is essential for structure–property relations. A series of polycyclic aromatic hydrocarbon (PAH)‒1,2,4,5-tetracyanobenzene (TCNB) complexes cocrystals are grown directly on the substrate, with the morphology tunable from 1D needle-like to 2D plate-like on demand. Spatially resolved photoluminescence spectra analyses on different cocrystals display morphology dependent and anisotropic optical waveguiding properties. In situ observation and energy calculations of the crystallization processes reveal the formation mechanism being from a competition between growth kinetics-defined crystal habit and the thermodynamics driving force. This growth technique may serve the future demand for tunable morphology organic cocrystals in different functional applications.

The emergence of organic–inorganic halide perovskites has reformed the research status of optoelectronics to a great extent. The bulk single crystals of halide perovskite, which in theory reflect the intrinsic physical properties of the material, are however hard to integrate into functional devices. Just as in the case that silicon wafers have revolutionized modern industries including electronics and solar cells, the availability of perovskite crystal wafers may pave the way to functional devices. Here we designed a new settled temperature and controlled antisolvent diffusion system to precisely control all key factors that affect the supersaturation metastable zone during the crystal growth process, to grow MAPbBr3 single crystals more than 50 mm in size. Second, we fabricated MAPbBr3 single crystal wafers with different orientations, specifically, the (100), (010), (001), (110), and (111) wafers, with high crystalline quality (half-peak width of rocking curve of 60–100 arc sec). Some key parameters were measured and compared on the wafers, where the results hint that anisotropy of carrier transport may exist for this pseudocubic structure. We hope the availability of oriented single-crystal wafers can provide more scientists the materials and devices to clarify the debatable physicochemical properties and to integrate the wafers as active layers or substrates in optoelectronic devices.

In Table 3 of this Communication, the chemical structures of the substituents of products 8 q and 8 r were inadvertently switched. The correct entries are shown here. In Table 4, the structures of the major isomers 12 a and 12 c were printed incorrectly. The correct structures are shown here. The editorial office apologizes for these oversights. Table 3: Catalytic asymmetric hydrogenation of quinoline derivatives. [a] Entry R Product Yield [%] ee [%] Config 17 8 q > 99 [c] 90 R 18 8 r > 99 [c] 95 R