Surface recombination is a major bottleneck for realizing highly efficient micro/nanostructure solar cells. Here, parametric studies of the influence of Si microwire (SiMW) surface‐facet orientation (rectangular with flat‐facets, {110}, {100} and circular), with a fixed height of 10 µm, diameter (D = 1.5–9.5 µm), and sidewall spacing (S = 2.5–8.5 µm), and mesh‐grid density (1–16 mm⁻²) on recombination and carrier collection in SiMW solar cells with radial p‐n junctions are reported. An effective surface passivation layer composed of thin thermally grown silicon dioxide (SiO₂) and silicon nitride (SiN_x) layers is employed. For a fixed D of 1.5 µm, tight SiMW spacing results in improved short‐circuit current density (J_sc = 30.1 mA cm⁻²) and sparse arrays result in open‐circuit voltages (V_oc = 0.552 V) that are similar to those of control Si planar cells. For a fixed S, smaller D results in better light trapping at shorter wavelengths and higher J_sc while larger D exhibits better light trapping at larger wavelengths and a higher V_oc. With a mesh‐grid electrode the power conversion efficiency increases to 15.3%. These results provide insights on the recombination mechanisms in SiMW solar cells and provide general design principles for optimizing their performance.

中文翻译：

---

{110}，{100}和圆形硅微线太阳能电池中的表面钝化和载流子收集

表面重组是实现高效的微米/纳米结构太阳能电池的主要瓶颈。在此，以固定高度为10 µm，直径（D = 1.5–9.5 ）的硅微线（SiMW）表面刻面取向（矩形与平坦的刻面，{110}，{100}和圆形）的影响进行参数研究。报告了带有径向p-n结的SiMW太阳能电池在重组和载流子收集时的侧壁间距（S = 2.5–8.5 µm）和网栅密度（1–16 mm ^-2）。使用有效的表面钝化层，该表面钝化层由薄的热生长二氧化硅（SiO ₂）和氮化硅（SiN _x）层组成。对于固定的D间距为1.5 µm时，紧密的SiMW间距可改善短路电流密度（J _sc = 30.1 mA cm ^-2），而稀疏阵列会产生类似于控制Si平面的开路电压（V _oc = 0.552 V）细胞。对于固定的S，较小的D会在较短的波长和较高的J _sc下捕获更好的光，而较大的D会在较大的波长和较高的V _oc处捕获更好的光。。使用网状电极时，功率转换效率提高到15.3％。这些结果为SiMW太阳能电池的重组机制提供了见识，并为优化其性能提供了通用设计原理。