Material studies regarding InP-based high-efficiency solar cells

Abstract Aiming at the improvement of the conversion efficiency of a monolithic high-efficiency multi-junction solar cell based on the lattice constant of InP different types of low-band gap n/p solar cells were prepared on the lattice constant of InP via metal organic chemical vapor deposition (MOCVD) using only non-gaseous, so-called alternative precursors like tertiarybutylphosphine (TBP). Employing this less-toxic precursor compared to phosphine an InP single n/p solar cell was prepared as reference yielding the highest internal quantum efficiency reported in the literature. New materials were introduced on the lattice constant of InP, in particular GaAsSb ( E gap = 0.7 5 eV ) and InAlGaAs ( E gap = 1.0 3 eV ) . The new absorber materials were compared to more established materials like InGaAs ( E gap = 0.7 5 eV ) and InGaAsP ( E gap = 1.0 3 eV ) . It will be shown that the latter cell with 18% Al reached an internal quantum efficiency close to that of the InGaAsP cell.