The solvent ratio is about right for separating chlorophyll and plant pigments on a TLC plate. When you say the chlorophyll was at the top do you mean with the solvent front? If this is the case the mixture is too polar. The carotenes (orange to yellow band) should be at the solvent front with a cellulose band behind this (say at an Rf of 0.8). Carotenoids (rather than carotene) however are polar molecules and may be stuck to the base line (Rf=0) as an orange-brown band. I can't give you any reference as this is from experience. I would have used methyl ethyl ketone (MEK)/Pet Ether or cyclohexanone/Pet Ether mixtures but you are probably limited by the lab experiment.
The wikipedia reference below gives you the difference between carotene and carotenoid.