Schimper, H.-J.; Kollonitsch, Z.; Möller, K.; Seidel, U.; Bloeck, U.; Schwarzburg, K.; Willig, F.; Hannappel, T.: New materials for InP-based high efficiency solar cells. In: Palz W. [u.a.] [Eds.] : Twentieth European Photovoltaic Solar Energy Conference : proceedings of the international conference held in Barcelona, Spain, 6 - 10 June 2005München: WIP-Renewable Energies, 2005. - ISBN 3-936338-19-1, p. 492-494
Abstract:
Unfortunately, no appropriate III-V compound has been found yet with a band gap in the range of 1eV and the lattice constant of Ge or GaAs. In contrast, III-V semiconductors with band gaps in the range of 1 eV can be grown epitaxially on the lattice constant of InP. The materials science challenge arises here for the higher band gaps. Nevertheless, it appears worthwhile to explore the possibilities of low band gap material based on the InP lattice constant. All III-V compounds were grown via MOCVD using only non-gaseous, i.e. less toxic, precursors like TBP and TBAs instead of PH3 and AsH3. Employing TBP a InP n/p solar cell was prepared as reference cell yielding a similar or even higher internal quantum efficiency (IQE) than the best InP cell reported in the literature. InAlGaAs was employed as a n/p cell for the 1eV band gap range. Its QE was compared with the QE of the more established III-V-compound InGaAsP. Different InGaAsP n/p solar cells with band gaps in the range 0.9eV<Egap<1.2eV were fabricated and their performance will be discussed.