Contact resistivity (ρ_c) for silicon solar cells is often measured using a pseudo-TLM pattern of equally spaced gridlines, which is cut from the cell itself. In this measurement, the uncontacted (floating) gridlines between two contacted gridlines are usually assumed to be disconnected from the silicon sheet. Analysis of such TLM data yields an approximate value of ρ_c, which is reasonably accurate for L_T/L > 1, but increasingly less accurate for L_T/L < 1 (good contacts). In this article, the TLM analysis is extended to explicitly include the effect of uncontacted gridlines to provide a more accurate analysis of gridline TLM data. Three contact systems were measured and then analyzed by both the approximate and improved methods. In all cases, a commercial Ag paste was screen printed and fired through a dielectric coating (SiN_x/AlO_x or SiN_x) to contact a p⁺-poly (p-TOPCon) layer, an n⁺-poly (n-TOPCon) layer, or a p⁺-boron (p-diffused) layer. The improved TLM analysis gave ρ_c values of 3.51, 0.89, and 5.26 mΩ·cm², respectively. Analysis of the n-TOPCon data is complicated by 2-D current flow across the tunneling oxide and into the n-substrate, with corresponding uncertainty. Expressions for converting ρ_c to a component of series resistance are also given. Additional calculations were carried out to determine ρ_c error with approximate TLM analysis. With assumed L_T/L values of 1, 0.5, and 0.25, the errors are 3.7%, 41%, and 280%, respectively.

中文翻译：

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网格线 TLM 模式的改进分析，包括非接触网格线的影响

接触电阻率 (ρ _c) 对于硅太阳能电池，通常使用等距网格线的伪 TLM 图案进行测量，该网格线是从电池本身切下的。在该测量中，通常假设两条接触网格线之间的非接触（浮动）网格线与硅片断开。对此类 TLM 数据的分析产生了一个近似值ρ _c，这是相当准确的 长_吨/升 > 1，但越来越不准确 长_吨/升< 1（良好的接触）。在本文中，TLM 分析被扩展为明确包括非接触网格线的影响，以提供对网格线 TLM 数据的更准确分析。测量了三个接触系统，然后通过近似方法和改进方法进行了分析。在所有情况下，商业银浆都被丝网印刷并通过介电涂层（SiN_X/氧化铝_X 或氮化硅_X) 接触 ap ⁺ -poly (p-TOPCon) 层、n ⁺ -poly (n-TOPCon) 层或 ap ⁺ -boron (p-diffused) 层。改进的 TLM 分析给出了ρ _c分别为 3.51、0.89 和 5.26 mΩ·cm ^{2 的值}。n-TOPCon 数据的分析因穿过隧道氧化物并进入 n 衬底的二维电流而变得复杂，并具有相应的不确定性。转换表达式ρ _c还给出了串联电阻的组成部分。进行了额外的计算以确定ρ _c近似 TLM 分析的错误。假设长_吨/升 1、0.5 和 0.25 的值，误差分别为 3.7%、41% 和 280%。