Which factors contribute to inefficiencies in silicon-based photovoltaic devices in harvesting the e — Physical Chemistry Chemistry Question

Which factors contribute to inefficiencies in silicon-based photovoltaic devices in harvesting the energy of light from the sun?
I. Photons with energies less than the band gap of silicon are not absorbed by the device.
II. Energy is lost as heat when photons with energies greater than the band gap of silicon are absorbed by the device.