Each solution is less than 100% efficient. For example, a photovoltaic cell captures between 6% and 40% of the available energy depending on the type of cell. The excess energy is converted to heat, which is lost as 'rejected energy'.
That got me thinking that it should be possible to stack these technologies. In this case, a combined stack of polymer/photovoltaic/thermal generator layers should be able to each use what is the waste product of the others.. Yet I find very little information about this in the search engines. That's got to be possible, right?"