ABSTRACT
The photoluminescence of organic crystals has been used to study the energy trans fer processes in the solids [87]; it is primarily a random walk to nearest-neighbor molecules, keeping the walk until luminescence does take place or until it steps onto an absorbing site, in which case it is completely absorbed without lumines cence. However, the charge transfer can also take place in many fields, such as in molecular heterojunctions at the molecular level [88], in quantum wells [89-91], and in the band-to-band transition approach in polymers to enhance organic elec troluminescent intensity and efficiency [24]. It was found very effective that the operating mechanism of optic and electronic devices was studied by analyzing the photoluminescence of the mixed materials.
