PROJECT TITLE :

Latest Developments of High-Efficiency Micromorph Tandem Silicon Solar Cells Implementing Innovative Substrate Materials and Improved Cell Design

ABSTRACT:

We report on the most recent analysis developments of micromorph (amorphous/microcrystalline) tandem silicon solar cells in our laboratory. We show that an improved cell design based mostly on the employment of silicon-oxide-doped layers permits high efficiencies on substrates that are sometimes considered as inappropriate for microcrystalline silicon (μc-Si:H) growth. Furthermore, advanced superstrates have recently been developed based on, e.g., multiscales textures, ultraviolet nanoimprint lithography, and bilayers, leading to very promising results. Whereas efficiencies of twelve.seven% initial and eleven.three% stable were achieved with a bottom cell that is solely one.one μm thick on a rough front zinc oxide electrode, a high twelve% initial potency was additionally reached on a textured replica. Our lab conjointly placed emphasis on increasing the deposition rate of μc-Si:H, and we tend to observed that top depletion conditions cause dense, high-quality material. So far, conversion efficiencies up to 8.five% are achieved with single-junction one.8-μm-thick μc-Si:H solar cells deposited at one nm/s. We tend to also report a promising initial efficiency of twelve.1% for a micromorph cell with a one-μm-thick bottom cell, for that the absorber layer was grown at 1 nm/s.