Optical and electrical properties of five polymers are investigated in solution and thin film forms. All the polymers exhibit strong absorption peak in the UV region, at about 295 nm (4.2 eV) the peaks is attributed to biphenyl mesons in the pendants of the polymers. The excitation power dependent Photoluminescence (PL) are carried out in THF solution with different concentrations. The integrated PL intensities are found to increase linearly with power, and saturate at high concentration....[ Read more ]

Optical and electrical properties of five polymers are investigated in solution and thin film forms. All the polymers exhibit strong absorption peak in the UV region, at about 295 nm (4.2 eV) the peaks is attributed to biphenyl mesons in the pendants of the polymers. The excitation power dependent Photoluminescence (PL) are carried out in THF solution with different concentrations. The integrated PL intensities are found to increase linearly with power, and saturate at high concentration.

The power dependent PL and excitation polarization dependent PL are performed. In comparison with the PL spectra in solution, only a single peak at 460 nm is observed in thin film while peaks at 380 nm and 460 nm are observed in solution. The disappearing of 380 nm peak is attributed to the strong interaction within the molecules in thin film form. The maximum PL intensity appear at an angle 75^o differ (120^o - 45^o) from the excitation maximum. This implies that the polymer are aligned along a particular direction in the process of making thin film, and this discovery is important for further applications.

The simple three-layer structure (ITO/polymer/Al) device is made. The I-V characteristic for the device is measured, however no EL can be detected from the device. This may due to the insufficient current injection.