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Mesoporous nanoflakes Cu 2 S counter electrode (CE) was prepared from three-dimensional ordered macroporous (3-DOM) Cu film obtained by polystyrene microspheres assisted potentiostatic deposition for quantum dot-sensitized solar cell (QDSSC). The structrue of the Cu 2 S CE can be controlled by the size of polystyrene microspheres. The optimized Cu 2 S CE shows a charge transfer resistance (R CT ) as low as 1.24 Ω cm 2 , while the R CT of the Pt CE is 2250 Ω cm 2 . A CdSe QDSSC based on the mesoporous nanoflakes Cu 2 S CE achieved a power conversion efficiency of 6.01%, which was higher than that based on Pt CE (1.74%) and ordinary Cu 2 S CE (4.85%). This enhancement can be attributed to the increased surface area, the easy electrolyte diffution and the improved electron transport of mesoporous nanoflakes Cu 2 S CE. This work provides a new effective approach for the structure control of Cu 2 S CE for high-efficiency QDSSC. [ABSTRACT FROM AUTHOR]

A new series of cerium-substituted Y 2 W 3 O 12 ceramics were first fabricated with the goal of tailoring the thermal expansion and reducing the hygroscopicity. Influence of cerium substitution on the structure, hygroscopicity and thermal expansion property of Y 2 W 3 O 12 ceramics were investigated using XRD, FESEM, HRTEM, XPS, TGA and TMA. Results indicate that the Y 3+ can partly be substituted by Ce 3+ in Y 2- x Ce x W 3 O 12 ceramics and increasing substitution of Y 3+ in Y 2 W 3 O 12 by Ce 3+ results in the crystal structure change from orthorhombic to monoclinic. Single-phase Y 2- x Ce x W 3 O 12 ceramics can be synthesized in the range of 0.0 ≤ x ≤ 0.25 with an orthorhombic Y 2 W 3 O 12 -type crystal structure and 1.0 < x ≤ 2.0 with monoclinic Ce 2 W 3 O 12 -type crystal structure, respectively. As the amount of substituted cerium increases, the hygroscopic phenomenon of Y 2- x Ce x W 3 O 12 is significantly promoted, meanwhile the coefficient of thermal expansion gradually decreases. The linear coefficient of thermal expansion of Y 2- x Ce x W 3 O 12 ceramics can be adjusted from −13.094 × 10 −6  K −1 to 2.327 × 10 −6  K −1 by changing the substituted amount of cerium. Moreover, Y 0.25 Ce 1.75 W 3 O 12 does not absorb moisture in air and shows almost zero thermal expansion from 182 °C to 700 °C and its coefficient of thermal expansion is tested to be −0.820 × 10 −6  K −1 . This low thermal expansion Y 0.25 Ce 1.75 W 3 O 12 material may have great potential applications in manufacturing precision device in many fields. [ABSTRACT FROM AUTHOR]