1. Damp-Heat-Stable, High-Efficiency, Industrial-Size Silicon Heterojunction Solar Cells
- Author
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Stefaan De Wolf, Wenzhu Liu, Lingling Yan, Jingxuan Kang, Jun Peng, Fanying Meng, Lujia Xu, Kai Wang, Xinbo Yang, Renfang Chen, Zhuopeng Wu, Zhengxin Liu, Liping Zhang, and Shi Jianhua
- Subjects
Amorphous silicon ,Materials science ,Passivation ,Band gap ,business.industry ,Doping ,Photovoltaic system ,Energy conversion efficiency ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Molecular dynamics ,General Energy ,chemistry ,Ab initio quantum chemistry methods ,Optoelectronics ,0210 nano-technology ,business - Abstract
Summary 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 SiNx and SiOx, 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.
- Published
- 2020