@article{Schnabel2018b,

title = {Equivalent Performance in Three-Terminal and Four-Terminal Tandem Solar Cells},

author = {M Schnabel and M Rienäcker and E L Warren and J F Geisz and R Peibst and P Stradins and A C Tamboli},

doi = {10.1109/JPHOTOV.2018.2865175},

issn = {2156-3381},

year  = {2018},

date = {2018-11-01},

journal = {IEEE Journal of Photovoltaics},

volume = {8},

number = {6},

pages = {1584-1589},

abstract = {Tandem or multijunction solar cells are a promising method to circumvent the efficiency limit of single-junction solar cells, but there is ongoing debate over how best to interconnect the subcells in a tandem cell. In addition to four-terminal and two-terminal tandem cell architectures, a new three-terminal tandem cell architecture has recently been demonstrated, which features a standard two-terminal (front-back) circuit as well as an interdigitated back contact (IBC) circuit connected to the bottom cell. It has no middle contacts, and thus, maintains some of the simplicity of a two-terminal tandem. In this study, we measure four-terminal GaInP//Si and GaInP/GaAs//Si tandem cells in four-terminal and three-terminal configurations by connecting wires to mimic a three-terminal architecture. We demonstrate that both modes allow the same efficiencies exceeding 30% to be attained. Furthermore, we show that the IBC circuit not only collects excess power from the bottom cell, but that it can inject power into the bottom cell if it is current limiting the front-back circuit, enabling four-terminal performance in monolithic structures, regardless of which cell delivers less current.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Schäfer2016,

title = {Light trapping and surface passivation of micron-scaled macroporous blind holes},

author = {S Schäfer and C Gemmel and S Kajari-Schröder and R Brendel},

doi = {10.1109/JPHOTOV.2015.2505179},

year  = {2016},

date = {2016-03-01},

journal = {IEEE Journal of Photovoltaics},

volume = {6},

number = {2},

pages = {397-403},

abstract = {We fabricate a blind hole surface texture by anodic etching of macroporous Si. The blind holes, i.e., pores that do not penetrate the wafer completely, have an average diameter of 2.7 μm, a distance of 4 μm, and a depth of 9 μm. This texture is capable of reducing the AM1.5G photon flux-weighted front reflectance to 1.5% without depositing an antireflection coating. The μm-feature size makes it a less fragile alternative to common nm-sized black silicon structures. We passivate the blind holes by atomic layer deposited AlOx. The blind hole texture allows for a carrier lifetime of (2.2 ± 0.25) ms corresponding to an effective surface recombination velocity of (8 ± 1.5) cm/s with respect to the macroscopic front surface. A direct comparison of the optical performance and the surface passivation quality with a standard SiNx-coated random pyramid surface shows that blind holes allow for a relative efficiency gain of (3 ± 0.2)% when applied, e.g., in an otherwise perfect back-contacted solar cell.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}