Solution-processed CuOx as an efficient hole-extraction layer for inverted planar heterojunction perovskite solar cells

A solution-processed CuOx film has been successfully integrated as the hole-transporting layer（HTL） for inverted planar heterojunction perovskite solar cells（PVSCs）. The CuOx layer is fabricated by simply spin-coating a copper acetylacetonate（Cu（acac）2） chloroform solution onto ITO glass with high transparency in the visible range. The compact and pinhole-free perovskite film with large grain domains is grown on the CuOx film. The inverted PVSCs with the structure of ITO/CuOx/MAPbI3/PC（61）BM/ZnO/Al are fabricated and show a best PCE of 17.43% under standard AM 1.5G simulated solar irradiation with a VOCof 1.03 V, aJ（SC） of 22.42 mA cm^（-2）, and a fill factor of 0.76, which is significantly higher and more stable than that fabricated from the often used hole-transporting material PEDOT：PSS（11.98%） under the same experimental conditions. The enhanced performance is attributed to the efficient hole extraction through the CuOx layer as well as the high-quality CH3NH3PbI3 films grown on the CuOx. Our results indicate that low-cost and solution-processed CuOx film is a promising HTL for high performance PVSCs with better stability.

Water Soluble Amino Grafted Silicon Nanoparticles and Their Use in Polymer Solar Cells

Stable aqueous amino-grafted silicon nanoparticles （SiNPs-NH2） were prepared via one-pot solution method. By grafting amino groups on the particle surface, the dispersion of SiNPs in water became very stable and clear aqueous solutions could be obtained. By incorporating SiNPs-NH2 into the hole transport layer of poly（3,4- ethylenedioxythiophene）/polystyrene sulfonic acid （PEDOT＇PSS）, the performance of polymer solar cells composed of poly[2-methoxy,5-（2＇-ethylhexyloxy）-1,4-phenylene vinylene] （MEH-PPV）：[6,6]-phenyl-C61-butyric acid methyl ester （PCBM） as active layer can be improved. SiNPs-NH2 are dispersed uniformly in the PEDOT：PSS solution and help form morphologies with small-sized domains in the PEDOT：PSS film. SiNPs-NH2 serve as screens between conducting polymer PEDOT and ionomer PSS to improve the phase separation and charge transport of the hole transport layer. As a result, the sheet resistance of PEDOT：PSS thin films is decreased from （93 ±5） × 10^5 to （13 ± 3） × 10^5 Ω/□. The power conversion efficiency （PCE） of polymer solar cells was thus improved by 9.8% for devices fabricated with PEDOT＇PSS containing 1 wt% of SiNPs-NH2, compared with the devices fabricated by original PEDOT：PSS.

PERFORMANCE ENHANCEMENT OF CdS NANOROD ARRAYS/P3HT HYBRID SOLAR CELLS VIA N719 DYE INTERFACE MODIFICATION

Improved hybrid solar cells consisting of vertical aligned cadmium sulfide （CdS） nanorod arrays and interpenetrating polythiophene （P3HT） have been achieved via modification of CdS nanorod surface by using conjugated N719 dye. The complete infiltration of P3HT between CdS nanorods interspacing was verified by scanning electron microscopy. By employing absorption and photoluminescence spectra, and current-voltage characterization the interaction between N719 molecules and CdS nanorods/P3HT interface was explored, and the role of N719 dye on the improvement of device performance was discussed.

Improved Photovoltaic Performance from High Quality Perovskite Thin Film Grown with the Assistance of PC71BM

The strategy of sequentially spin-coating a perovskite film from the perovskite precursor and an electron transporting layer of [6,6]-phenyl-C71-butyric acid methyl ester （PC71BM） is developed to simplify the fabrication procedure of perovskite solar cells. X-ray diffraction and scanning electron microscopy indicate that PCTIBM film on perovskite layer can retard the evaporation of dimethyl sulfoxide （DMSO） efficiently, thus prolonging the transformation of intermediate phase to perovskite crystals, leading to a high quality perovskite thin film. The solar cells with the structure of indium tin oxides （ITO）/poly（3,4-ethylenedioxythiophene）：poly（styrenesulfonate） （PEDOT：PSS）/CH3NH3PbI3/PC71BM/bathocuproine （BCP）/Ag made from this simplified method exhibit a higher efficiency （12.68%） than those from the conventional one-step method （9.49%）.