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α-Fe 2 O 3 /BiOCl heterojunctions were synthesized by growing and assembling α-Fe 2 O 3 nanoplates to BiOCl microflowers via a two-step route to enhance the photocatalytic performance of BiOCl. The morphology, microstructure, element composition and optical properties of α-Fe 2 O 3 /BiOCl heterojunctions have been investigated by SEM, TEM, XRD, FT-IR, Raman spectra, XPS, UV–vis diffuse reflectance and PL spectra. Electrostatic interaction was a key to form α-Fe 2 O 3 /BiOCl heterojunctions. Compared with pure BiOCl, the synthesized α-Fe 2 O 3 /BiOCl heterojunctions possess an efficient visible light absorption and exhibit an improved of photocatalytic efficiency. A photocatalytic degradation mechanism has been proposed to explain that the heterojunctions enhance the separation efficiency of electron-hole pairs, and the holes are the main reactive species in the degratation of Rhodamine B. [ABSTRACT FROM AUTHOR]

A compact layer (blocking layer) can effectively block the direct contact between the fluorine-doped tin oxide (FTO) glass substrate and electrolyte in dye-sensitized solar cells (DSSCs). The TiCl 4 hydrolysis has been widely adopted for preparing the TiO 2 compact layer (H-TiO 2 ). However, the TiCl 4 aqueous solution is unstable for its high reactivity. To improve the chemical stability of TiCl 4 aqueous solution, the Ti 4+ is encapsulated by the polymer, polyethyleneimine (PEI). Experimentals show that the Ti-PEI precursor solution can maintain their initial performances for several months. The resulting TiO 2 film (P-TiO 2 ) grown by the Ti-PEI precursor is dense, smooth and uniform without any visible and detectable cracks or voids. The P-TiO 2 compact layer is even denser than the H-TiO 2 compact layer, suggesting reducing the electron recombination and prolonging the electron lifetime in dye-sensitized solar cells. Indeed, the electron lifetime of the DSSC based on the P-TiO 2 is 13.15 ms, which is longer than the 10.83 ms based on H-TiO 2 . Meanwhile, the power conversion efficiency of the DSSC based on P-TiO 2 compact film is about 12.5% higher than that based on H-TiO 2 . Therefore, this encapsulation technology can not only improve the stability of the metal ions solution but also meet a large-scale fabrication demand of the TiO 2 compact layer in future DSSCs. [ABSTRACT FROM AUTHOR]

Abstract: A stable organic solar cell with structure of ITO/buffer/donor/acceptor/cathode is presented. A thin layer (5nm) of MoO3-doped CuPc is adopted as the buffer in CuPc/C60 organic heterojunction photovoltaic (PV) solar cells, resulting in two times longer lifetime. The surface morphology of buffer layer plays a decisive role in improving the stability. [Copyright &y& Elsevier]