A facile method for the synthesis of size-and shape-controlled CuInS 2 semiconductor nanocrystals was developed by thermolysis of a mixed solution of CuAc, In(Ac) 3 (molar ratio of CuAc to In(Ac) 3 ) 1:1) and dodecanethiol in noncoordinating solvent 1-octadecene (ODE) at 240 °C. CuInS 2 nanoparticles with size of 2 to ∼5 nm and nanorods with aspect ratio of 1 to ∼3 were obtained by adjusting the reaction parameters such as temperature and time. The as-prepared nanoparticles were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy, selected area electron diffraction spectroscopy, inductively coupled plasma atomic emission spectroscopy, UV-vis absorption, and photoluminescence (PL) spectroscopy. The nanoparticle solutions exhibit tunable absorption and PL spectra with the absorption edge ranging from 550 to 750 nm and PL emission peaks from 600 to 750 nm, indicating a strong size-dependent quantum confinement effect. Optical measurements of the CuInS 2 nanoparticles demonstrated that their optical properties are related to donor-acceptor defects, size-dependent quantum confined effects, and surface defects. The PL decay curve of CuInS 2 nanoparticles has a triple exponential characteristic with lifetimes of 4-12, 28-60, and 140-300 ns, respectively, and the PL emission with the longest lifetime (140-300 ns) occupied 40-80% of the PL emission of the samples. These results imply that the room-temperature PL emission of CuInS 2 nanoparticles involves three types of recombination: band exciton recombination, surface-related recombination, and donor-acceptor defects recombination. Among them, the PL emission from donor-acceptor defects occupied a large amount.

Single‐crystalline Sb2Se3 nanowires demonstrate excellent field‐emission and photodetector properties for the first time. They show low turn‐on (2.6 V μm−1) and threshold voltages (4.9 V μm−1) and a high enhancement factor (3466). The individual Sb2Se3 nanowire photodetectors exhibited a marked response to visible light (Rλ and EQE are as high as ∼8.0 A/W and ∼1650%, with a response time of less than 0.3 s).

A facile route for synthesizing CuInSe2 nanocrystals was developed using an alkanethiol as ligand and noncoordinating octadecene as solvent. The CuInSe2 nanoparticles and nanoplates were obtained, depending on the reaction temperature and time. When the reaction temperature was set at 180 °C and reaction for an hour, CuInSe2 nanoparticles with an average size of 6.2 nm were produced. As the reaction time was prolonged to 3 h, nanoplates appeared inside the nanoparticles. When the reaction temperature was elevated to 210 °C and reaction for 3 h, triangular or hexagonal CuInSe2 nanoplates with sharp edges were synthesized. It was proposed that the Ostwald ripening induced the morphology evolution of the CuInSe2 nanoparticles into nanoplates at the higher temperature. The nanoparticles and nanoplates were characterized by transmission electron microscopy (TEM), selected area electron diffraction (SAED), x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). The UV–vis absorption spectra of the CuInSe2 nanoparticles were significantly blue-shifted in comparison with the bulk material due to the quantum confinement.

Composition‐tunable ZnxCd1–xS alloyed nanocrystals have been synthesized by a new approach consisting of thermolyzing a mixture of cadmium ethylxanthate (Cd(exan)2) and zinc ethylxanthate (Zn(exan)2) precursors in hot, coordinating solvents at relatively low temperatures (180–210 °C). The composition of the alloyed nanocrystals was accurately adjusted by controlling the molar ratio of Cd(exan)2 to Zn(exan)2 in the mixed reactants. The alloyed ZnxCd1–xS nanocrystals prepared in HDA/TOP (HDA: hexadecylamine; TOP: trioctylphosphine) solution exhibit composition‐dependent shape and phase structures as well as composition‐dependent optical properties. The shape of the ZnxCd1–xS nanocrystals changed from dot to single‐armed rod then to multi‐armed rod with a decrease of Zn content in the ternary nanoparticles. The alloying nature of the ZnxCd1–xS nanocrystals was consistently confirmed by the results of high‐resolution transmission electron microscopy (HRTEM), X‐ray diffraction (XRD), and UV‐vis absorption and photoluminescence (PL) spectroscopy. Further, the shape‐controlled synthesis of the ternary alloyed nanocrystals was realized by selecting appropriate solvents. Uniform nanodots in the whole composition range were obtained from TOPO/TOP solution, (TOPO: trioctylphosphine oxide) and uniform nanorods in the whole composition range were prepared from HDA/OA solution (OA: octylamine). The effect of the reaction conditions, such as solvent, reaction temperature, and reaction time, on the PL spectra of the alloyed ZnxCd1–xS nanocrystals was also systematically studied, and the reaction conditions were optimized for improving the PL properties of the nanocrystals.

A series of [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM)‐like fullerene derivatives with the butyl chain in PCBM changing from 3 to 7 carbon atoms, respectively (F1–F5), are designed and synthesized to investigate the relationship between photovoltaic properties and the molecular structure of fullerene derivative acceptors. F2 with a butyl chain is PCBM itself for comparison. Electrochemical, optical, electron mobility, morphology, and photovoltaic properties of the molecules are characterized, and the effect of the alkyl chain length on their properties is investigated. Although there is little difference in the absorption spectra and LUMO energy levels of F1–F5, an interesting effect of the alkyl chain length on the photovoltaic properties is observed. For the polymer solar cells (PSCs) based on P3HT as donor and F1–F5, respectively, as acceptors, the photovoltaic behavior of the P3HT/F1 and P3HT/F4 systems are similar to or a little better than that of the P3HT/PCBM device with power conversion efficiencies (PCEs) above 3.5%, while the performances of P3HT/F3 and P3HT/F5‐based solar cells are poorer, with PCE values below 3.0%. The phenomenon is explained by the effect of the alkyl chain length on the absorption spectra, fluorescence quenching degree, electron mobility, and morphology of the P3HT/F1–F5 (1:1, w/w) blend films.

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A novel ligand tuning strategy for the synthesis and assembly of ZnTe nanocrystals is proposed in this paper: a specific ligand is selected to work with the reaction system to regulate (passivate or activate) the reactivity of zinc precursors, as well as the growth and the assembly of resulting nanocrystals in a coordinate way. By utilization of this strategy, high-quality ZnTe nanodots, branched-nanorods (including nanotetrapods), nanowires and microspheres are obtained. Furthermore, by using ZnTe microspheres as building blocks, ordered two-dimensional (2D) and three-dimensional (3D) arrays and well-defined hollow microspheres are fabricated. The size, morphology, and crystal structure of asprepared ZnTe nanocrystals are well characterized. The underlying mechanisms for ligand-tuned synthesis and assembly of ZnTe nanocrystals are also intensively discussed. Finally, the shapedependent optical, structural, and electrochemical properties of those ZnTe nanocrystals are systemically investigated; their band edge positions are studied by cyclic voltammetry.