Long ago, say, in the 1960's, it was true that solar cells did not return the energy of their manufacture. In those days, cells were 4% efficient, and made with more material and a less efficient process. Unfortunately, the myth persists that this is still the case today from unaccredited sources.
Kudos to Michael for the nrel link. That study was actually done over 10 years ago, and since then, technology has advanced even further. Manufacturers have been able to reduce the thickness of cells in general in the last decade, to use less crystalline silicon. Also manufacturers such as Suntech with their "pluto" process are now able to use a lower grade of silicon, that takes less energy to refine. The result is that the energy payback time is even shorter today than estimated in the linked paper.