NOVEL OPTIMIZATION PRINCIPLES AND EFFICIENCY LIMITS FOR SEMICONDUCTORSOLAR-CELLS

Quantum efficiencies of more than merely one electron-hole pair per ab sorbed photon have recently been demonstrated for solar cells. The the oretical upper limit for solar cell conversion efficiency can thus be raised (from 30%) to 43% if photon absorption and electron-hole excita tion follow a specific pathway. This pathway includes photon absorptio n at specific points in the Brillouin zone, and an inverse Auger effec t mechanism for the multiplication of electron-hole pairs. We specify the principles and rules for optimal band structure tailoring.