They contain the chlorophyll which are essential pigments for harvesting solar energy in photosynthetic systems. Chloroplast's role is multifaceted, in not only carrying out the photosynthesis ...

Trurnit, H. J., and Colmano, G., Biochim. Biophys. Acta, 31, 434 (1959).

Chlorophyll is found in plants – more specifically, it’s the green pigment found in the chloroplast. “Chlorophyll is the stuff that helps absorb sunlight during a process called photosynthesis.