Transport imaging of multi-junction and CIGS solar cell materials
Ong, Zi Xuan.
Haaegel, Nancy M.
MetadataShow full item record
Multi-junction solar cells are an emerging technology that improves the conversion rate of solar energy. Indium Gallium Phosphide (InGaP) is commonly used as the top cell in multi-junction cells grown on Germanium (Ge) or Gallium Arsenide (GaAs) substrates. To design more efficient solar cells using InGaP, it is important to characterize its transport parameters, particularly the minority charge carrier mobility, diffusion length and lifetime as a function of doping and material growth conditions. In this work, transport imaging was performed on a set of InGaP heterostructures (with differing thicknesses, doping levels and minority carrier types) to determine their minority carrier diffusion length. These measurements, together with an independent set of time-resolved photoluminescence (TRPL) lifetime data, were used to calculate the minority carrier mobility values. For the shortest diffusion lengths, experimental limitations were encountered involving the finite carrier generation volume. Simulations were performed to explore the potential of modeling the convolution of diffusion behavior with a finite generation region to address these limitations. Transport imaging was also performed on a set of Copper Indium Gallium Selenide (CIGS) materials. Polycrystalline CIGS represents an alternative to the expensive single-crystal InGaP. These initial experiments identified the challenges of applying transport imaging to polycrystalline materials.
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Haegel, N.M.; Mills, T.J.; Talmadge, M.; Scandrett, C.L.; Frenzen, C.L.; Yoon, H.; Fetzer, C.M.; King, R.R. (IEEE., 2009);An all-optical technique has been used to provide the first direct measurement of anisotropic minority-carrier diffusion in an ordered alloy of GaInP. Direct imaging of the minority-carrier diffusion distribution resulting ...
Rauscher, Brian Craig (Monterey California. Naval Postgraduate School, 2008-06);The goal of this thesis is to explore the utility of in-situ optical imaging of charge transport imaging in multi junction solar cells. An in-situ measurement of a manufactured solar cell's key material parameters is ...
Cole, Richard Adam (Monterey, California. Naval Postgraduate School, 2010-12);A novel technique for imaging minority carrier diffusion in semiconductor nanostructures has been applied to the characterization of GaN and ZnO nanowires and nanobelts. Near field scanning optical microscopy (NSOM) is ...