Department of Materials and Chemical Engineering, Hanyang University, Ansan, 426-791, Korea.
Nanoscale. 2014 May 21;6(10):5193-9. doi: 10.1039/c4nr00455h.
Formation of a selective emitter in crystalline silicon solar cells improves photovoltaic conversion efficiency by decoupling emitter regions for light absorption (moderately doped) and metallization (degenerately doped). However, use of a selective emitter in silicon nanowire (Si NW) solar cells is technologically challenging because of difficulties in forming robust Ohmic contacts that interface directly with the top-ends of nanowires. Here we describe a self-aligned selective emitter successfully integrated into an antireflective Si NW solar cell. By one-step metal-assisted chemical etching, NW arrays formed only at light-absorbing areas between top-metal grids while selectively retaining Ohmic contact regions underneath the metal grids. We observed a remarkable ∼40% enhancement in blue responses of internal quantum efficiency, corresponding to a conversion efficiency of 12.8% in comparison to the 8.05% of a conventional NW solar cell.
在晶体硅太阳能电池中形成选择性发射极可以通过将用于光吸收（中等掺杂）和金属化（简并掺杂）的发射极区域解耦来提高光伏转换效率。然而，由于在与纳米线顶端直接接口的位置形成稳定欧姆接触存在技术挑战，因此在硅纳米线（Si NW）太阳能电池中使用选择性发射极是具有挑战性的。在这里，我们描述了一种成功集成到抗反射 Si NW 太阳能电池中的自对准选择性发射极。通过一步金属辅助化学蚀刻，只有在顶部金属栅极之间的光吸收区域形成 NW 阵列，而选择性地保留金属栅极下方的欧姆接触区域。我们观察到内部量子效率的蓝色响应显著提高了约 40%，与传统 NW 太阳能电池的 8.05%相比，转换效率达到了 12.8%。
