Optimization of tunnel-junction IBC solar cells based on a series resistance model

Transparent silicon carbide/tunnel SiO2 passivation for c‐Si solar cell front side: Enabling Jsc > 42 mA/cm2 and iVoc of 742 mV

“…For a wafer thickness of 165 μm, the estimated practical limit for iV oc is 748 mV according to Yoshikawa et al 23 To achieve such values close to the practical limit, Taguchi et al 22 claim that an ultraclean surface is needed, which was not assured for the sample preparation of this work as the HWCVD growth of μc-SiC: the great potential of this layer. To further increase the transparency of the μc-SiC:H(n), a possible way is to increase the filament temperature during the HWCVD growth of μc-SiC:H(n) as it was reported before in previous studies., 6,7 However, we also reported in Köhler et al 7 26,28 and which also follow the idea of simple fabrication process. On high-quality c-Si wafer, with τ bulk = 12 ms, we calculated 26.6% for η, 42.24 mA/cm 2 for J sc , 738 mV for V oc , and 85.2% for FF.…”

“…On low‐cost wafer, it gives rise to an efficiency of 25.2% and a J sc of 42.0 mA/cm 2 . This is in the range of tunnel‐junction IBC solar cells, which achieved a certified η of 25.0% and J sc of 41.7 mA/cm 2 very recently and which also follow the idea of simple fabrication process. On high‐quality c‐Si wafer, with τ bulk = 12 ms, we calculated 26.6% for η, 42.24 mA/cm 2 for J sc , 738 mV for V oc , and 85.2% for FF.…”

A Highly Conductive Titanium Oxynitride Electron‐Selective Contact for Efficient Photovoltaic Devices

“…Nevertheless, with an ultrathin TiOxNy capping layer ( 2.5 nm) over a-Si:H, the c of n-Si/a-Si:H/TiOxNy/Al heterocontact is  78 m.cm 2 , which is higher than the best reported c of conventional SHJ electron contact measured by transfer length method ( 30 m.cm 2 ). [33,34] Note, however, that the c extracted by the Cox and Strack method can be considered as the upper limit value for the a-Si:H/TiOxNy/Al heterocontact, because it comprises the resistance of the front a-Si:H/TiOxNy/Al and rear n-Si/Al interfaces as well as the a-Si:H and TiOxNy bulk resistivity. Thanks to the reduced c at the n-Si/TiOxNy/Al and n-Si/a-Si:H/TiOxNy/Al heterocontacts, which are the well below the c threshold ( 100 m.cm 2 ) of a full-area contact for high efficiency c-Si solar cells, [15,35] Rs and FFs of the corresponding devices are significantly improved, as shown in Table 1.…”

Lateral transport in silicon solar cells

“…For the n-contact, lower values down to 50 mΩ cm 2 are given. The latter can be considered as a good n-contact [28,29,32,33]. As can be seen from Fig.…”