Jian Xigao

Materials and devices research of PPV-ZnO nanowires for heterojunction solar cells

Bulk heterojunction photovoltaic devices, which use the conjugated polymer poly(2-methoxyl-5-(2′-ethylhexyloxy)-1,4- phenylenevinylene) (MEH-PPV) as the electron donor and crystalline ZnO nanowires as the electron acceptor, have been studied in this work. The ZnO nanowires were prepared through a chemical vapor deposition mechanism. The dissolved MEH-PPV polymer was spin-coated onto the nanowires. The scanning electron microscope images showed that the ZnO nanowires were covered with a single layer of the polymer, and these materials were used to design a heterojunction solar cell. This solar cell displayed improved performance compared with the devices that were made from only the MEH-PPV polymer. This observed improvement is correlated with the improved electron transport that is perpendicular to the plane of the film. A solar power conversion efficiency of 1.37% was achieved under an AM 1.5 illumination.

Synthesis of poly(aryl amide imide)s derived from o-diphenyltrimellitic anhydride

The synthesis and characterization of a series of novel poly (aryl amide imide) s based on odiphenyltrimellitic anhydride are described. The poly (aryl amide-imide) s having inherent viscosities of 0.39–1. 43 dL/g in N-methyl-2-pyrrolidinone at 30°C, were prepared by polymerization with aromatic diamines in N, N-dimethylacetamide and subsequent chemical imidization. All the polymers were amorphous, readily soluble in aprotic polar solvents such as DMAC, NMP, DMF, DMSO, and m-cresol, and could be cast to form flexible and tough films. The glass trsanition temperatures were in the range of 284–336°C, and the temperatures for 5% weight loss in nitrogen were above 468°C.