Spectral properties and frequency response of solid state cathodoluminescence based on MEH-PPV

The heterojunction of SiO2/MEH-PPV/SiO2 was prepared based on a layered optimization scheme. SiO2 was used as a electron acceleration layer, and MEH-PPV was taken as the luminescent material. Luminescence due to direct bombardment by accelerated electrons in a semiconductor thin film adjacent to the phosphor material layer was observed, which was called solid state cathodoluminescence (SSCL). In this paper we investigated the spectral properties and frequency response of SSCL. In three voltage ranges, the emission spectrum of the device changed. The red light was obtained when the voltage was low. In the higher voltage range, a blue light was observed. In the medium voltage range, the above two kinds of light coexist. The two types of emission resulted from the same electron bombardment of the MEH-PPV. The frequency response of blue emission was also studied