One approach to the utilization of solar energy is the development of devices that mimic natural photosynthesis. Such artificial photosynthesis efforts would be aided by a better understanding of the primary photochemical steps that occur in the natural process of photosynthesis. As a result our studies emphasize the mechanistic and structural detial of photosynthetic antenna system this appears to be crucial to the design of artificial solar energy devices. Chlorophyll a (Chl-a) has long been known as the major light-absorbing pigment in photosynthetic antenna systems Furthermore

the light absorbed by some carotenoides (accessory pigments) is photosynthesis active. The accessory pigments can transfer their absorbed energy to Chl-a Energy transfer has been considered the mechanism by Förster In types of artificial mono-layers

Chl-a and carotene (Car) are isolated from spinach in the usual manner of extraction followed by purification by column chromatography. In order to investigate the interaction between Chl-a and Car in a monolayer assembly

attempts are made to build up two different types of assembly on glass plate by conventional Langmuir-Blodgett techniques. One type is a monolayer film consisting of Chl-a and octadecoic acid with molar ratio of 1:10. As the artificial molecular monolayer of Chl-a forms aggregates

its fluorescence spectrum has a main peak at 677nm and a secondary peak at around 766nm(Fig.1). The main peak of Chl-a luminescence in the monolayer is shifted by 16nm to the long-wave band when compared with its state in the solution. This shift is apparently due to an increase of aggregate forms in the monolayer with respect to the solution. A new maximum (766nm) appears in the Chl-a fluorescence spectrum. It is due to the aggregate form of pigment The other type is a Car-Chl-a mixed monolayers with molar ratio 5:l;50:l;and 125:1 The two bands all appear in the cases of Car as donor and Chl-a as acceptor And then the luminescence intensities have nonlinear decay with the decrease of Chl-a molecule (Fig.2). The general idea is that Car helps the artificial antenna system to catch more of the incident light energy because they can take up excited light. The accessory pigments can transfer their absorbed energy to Chl-a Experiments show that the limited Förster transfer distance is about 100Å But as a result of the cooperation of exciton transfer and Förster transfer

the distance increaces. The result suggests that exciton transfer should play an important role in luminescence of biomimetic pigment films.