Photoelectric effect (generally ) is say absorption of photons causing transition and release of energy (following conservation of energy principle ) while thermal effects (as seen in transistors ) are increase in current (voltage reduces)
Coming to solar cell temperature vs efficiency (close to transistor idea)
Photoelectric cells are one of the best ways to generate electricity using solar cells to convert solar energy into electron flow. While in the case of solar energy, solar cells turn solar radiation into electrical energy, and despite the great benefit, during this process the amount of energy lost, and the amount of energy lost due to the temperature of solar cells is surprisingly large. This limits the cell's ability to efficiently transform energy, as well as reduce its lifetime.