The impact of intrinsic amorphous silicon bilayers in amorphous silicon/crystalline silicon (a‐Si:H/c‐Si) heterojunction solar cells is investigated. Intrinsic a‐Si:H films with a wide range of film densities and hydrogen contents are prepared via a plasma‐enhanced chemical vapor deposition (PECVD) technique by modifying various process parameters. For silicon heterojunction (SHJ) solar cells with a‐Si:H films applied as single i‐layers, the resulting surface passivation at the a‐Si:H/c‐Si interface is poor. However, surface passivation is significantly improved by applying intrinsic bilayers, which are composed of a porous interfacial layer (≈2 nm) and an overlying dense layer (≈8 nm). The microstructure factor R* of the interfacial a‐Si:H layer, which is related to the SiH bond microstructure and determined by infrared absorption spectroscopy, closely correlates to the surface passivation capability of the bilayers. A variety of PECVD process parameters (temperature, pressure, or precursor gas species) can be utilized to grow an interfacial layer for good surface passivation, provided that its R* is controlled within a suitable range. This indicates that R* is a key universal parameter for optimizing i‐bilayers and realizing high‐efficiency SHJ solar cells.

中文翻译：

---

硅异质结太阳能电池中有效表面钝化的本征非晶硅双层：界面层的比较研究

研究了非晶硅/晶体硅（a-Si：H / c-Si）异质结太阳能电池中本征非晶硅双层的影响。通过等离子增强化学气相沉积（PECVD）技术，通过修改各种工艺参数来制备具有宽膜密度和氢含量的本征a-Si：H膜。对于将a-Si：H膜用作单i层的硅异质结（SHJ）太阳能电池，在a-Si：H / c-Si界面处产生的表面钝化效果很差。但是，通过应用由多孔界面层（≈2nm）和上面的致密层（≈8nm）组成的本征双层，可以显着改善表面钝化。显微组织因子- [R的界面的a-Si的*：H层，其与所述Si H键的微观结构，并通过红外吸收光谱法测定，与双层的表面钝化能力密切相关。只要将其R *控制在合适的范围内，就可以利用各种PECVD工艺参数（温度，压力或前体气体种类）来生长界面层，以实现良好的表面钝化。这表明R *是优化i-双层和实现高效SHJ太阳能电池的关键通用参数。