CuInSe2 films were electrodeposited onto indium tin oxide(ITO) substrate in constant current mode using bell-like wave modulated square wave in aqueous solution.The films obtained at different pulse frequencies were characterized by scanning electron microscopy(SEM),X-ray energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD).UV-Vis-NIR absorption spectro scopy was used to study the optical properties of these films.The results showed that the chalcopyrite phase CuInSe2 films with a smooth surface and stoichiometric composition could be obtained at appropriate pulse frequency.The crystallinity of CuInSe2 films could be further improved after annealing treatment.Despite this,we also found that the films obtained using the pulse-plating electrodeposition technique had a faster deposition rate and better film adhesion ability than that using the traditional CIS electrodeposition technique,which is significant to the low-cost CIS thin film solar cell production.
WANG XiaoLi WANG GuangJun TIAN BaoLi WAN ShaoMing DU ZuLiang
Self-organized dithieno [3,2-b:2',3'-d] thiophene-2,5-dicarboxylic acid (A) and dithieno [2,3-b:3',2'-d] thiophene-2,5-dicarboxylic acid (B) films were prepared through solvent-induced order-disorder transition method.The arrangement of the two molecules on substrates were observed by atomic force microscopy (AFM),which demonstrated that A was arranged orderly in a certain angle on mica,while B was flat-flying on mica.The optical and conductance properties in micro region of these two compound films were characterized by UV-vis absorption spectroscopy,fluorescence spectroscopy and conductive atomic force microscopy (C-AFM).The results revealed that the fluorescence and absorption peaks of A had a large red shift in comparison with those of B.The conductance of the J-aggregates for A is three orders magnitude higher than that of B.It is concluded that the large conductance difference mainly comes from different aggregation structures and orientations of these two molecules on substrate.
WANG DeKun JIANG XiaoHong ZHAO ChunMei WANG ZhiHua WANG Hua DU Zu Liang
