Silicon heterojunction (SHJ) solar cells employ nanometer-thin stacks of intrinsic and doped hydrogenated amorphous silicon (a-Si:H) films as carrier-selective contacts. To achieve excellent carrier selectivity, the a-Si:H must be carefully optimized to guarantee an atomically sharp a-Si:H/c-Si interface. In this work, by combining experiments with molecular dynamics and ab initio calculations, we unveil that H atoms bonded to internal-void surfaces in a-Si:H broaden its optical band gap via a filamentary effect near the valence-band maximum. The photovoltaic performance of rear-emitter SHJ solar cells can be significantly improved by tailoring the Si−H bonding state in the front a-Si:H passivation layer, resulting in a power conversion efficiency (PCE) of 23.4% on a 6-in cell. By implementing double antireflection coatings (ARCs) of SiN_x and SiO_x, the PCE is further improved to 23.9%. More importantly, the ARC devices show prominently improved damp-heat stability without encapsulation in 1,000-h aging at 85°C, 85% relative humidity.

硅异质结（SHJ）的固有的太阳能电池采用纳米薄栈和掺杂的氢化非晶硅（一个-Si：H）膜作为载流子选择性的接触。为了实现优异的载流选择性，一个-Si：H必须仔细优化，以原子级尖锐保证的一个-Si：H / Ç -Si接口。在这项工作中，通过结合分子动力学实验和从头算计算，我们揭示了键合在-Si：H中的内部空隙表面上的H原子通过价带最大值附近的丝状效应扩大了其光学带隙。通过调整正面的Si-H键状态，可以显着提高后发射式SHJ太阳能电池的光伏性能一个-Si：H钝化层，导致23.4％的功率转换效率（PCE）在6细胞。通过实现SiN _x和SiO _x的双重抗反射涂层（ARC），PCE进一步提高到23.9％。更重要的是，ARC器件显示出显着改善的湿热稳定性，而无需封装在85°C，相对湿度为85％的条件下进行1000小时的老化。