TLM measurements varying the intrinsic a-Si:H layer thickness in silicon heterojunction solar cells

Transport Losses at the TCO/a-Si:H/c-Si Heterojunction: Influence of Different Layers and Annealing

“…The ITO/a-Si:H(p) interface, however, is a recombination junction. Holes in the a-Si:H(p) valence band have to recombine with electrons in the ITO conduction band [10], [33]. This will make the transport across this junction to also depend on efficient tunneling via trap states at suitable energy levels [34], [35].…”

“…Lachenal et al [5] coprocessed resistance test structures using the transfer length method (TLM) alongside solar cells, highlighting that the contact resistance represents the majority of the solar cell's series resistance. Their approach required patterning of the TCO via etching, whereas Leilaeioun et al [9] and Weigand et al [10] realized their TLM patterns via sputtering of TCO and silver contacts through shadow masks. By varying several parameters such as a-Si:H layer thickness and O 2 partial pressure during TCO deposition, they investigated the effect on ρ c and correlated the results with the fill factor (FF) and series resistance of corresponding solar cells.…”

Multiscale modeling of silicon heterojunction solar cells

“…However, most simulation studies have thus far treated the ITO as a Schottky contact whilst studying cell level properties[37]-[39].The simulations presented in this chapter complement experiments that were previously conducted by Leilaeiloun et al who used the TLM technique to measure the contact resistivity of an a-Si:H(i)/a-Si:H(p)/ITO(n + ) stack on a p-type c-Si wafer, and measured a contact resistivity as low as 0.1 Ω-cm 2 . Corresponding simulations calculated the contact resistivity (while treating the ITO as a semiconductor) by varying the a-Si:H(i) layer thickness and obtained agreement with experimental values[40]. This chapter describes a thorough analysis of transport through a hole contact stack [a-Si:H(i)/a-Si:H(p)/ITO(n + )] on p-type c-Si.…”

Lateral transport in silicon solar cells

“…Usually, the contact at the front-side of SHJ front-junction devices is the p-contact. For this contact, values in the range of 300-500 mΩ cm 2 are given in literature [13,17,[28][29][30][31]. For the n-contact, lower values down to 50 mΩ cm 2 are given.…”