Limiting Solar Cell Heat-Up by Quantizing High Energy Carriers

Under solar radiation the efficiency of solar cells decreases as a result of heating up by short wavelengths photons. To minimize loss of efficiency with increasing temperatures, we designed a heterostructure AlGaAs/AlGaAs/GaAs cascaded p-i-n solar cells with 30 Å wide quantum wells and 10 Å wide barriers in p and i regions. Our modeling demonstrated that quantizing high energy carriers in the superlattice prevents scattering of excessive electron energies, thus decreasing the temperature rise per unit of time by a factor of 2. The modeling based on continuity equations included integration of absorption coefficients for various wavelengths and summarizes all thermodynamic heat exchanges in the designed solar cell.