Adoption of wide-bandgap microcrystalline silicon oxide and dual buffers for semitransparent solar cells in building-integrated photovoltaic window system

• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2019,（8）
• 页码范围: 1563-1569
• 页数: 7页
• 语种: 英文

摘要

We focused on developing penetration-type semitransparent thin-film solar cells (STSCs) using hydrogenated amorphous Si (a-Si∶H) for a building-integrated photovoltaic (BIPV) window system.Instead of conventional p-type a-Si:H,p-type hydrogenated microcrystalline Si oxide (p-μc-SiOx∶H) was introduced for a wide-bandgap and conductive window layer.For these purposes,we tuned the CO2/SiH4 flow ratio (R) during p-μc-SiOx∶H deposition.The film crystallinity decreased from 50％ to 13％ as R increased from 0.2 to 1.2.At the optimized R of 0.6,the quantum efficiency was improved under short wavelengths by the suppression of p-type layer parasitic absorption.The series resistance was well controlled to avoid fill factor loss at R =0.6.Furthermore,we introduced dual buffers comprising p-a-SiOx∶H/i-a-Si∶H at the p/i interface to alleviate interracial energy-band mismatch.The a-Si∶H STSCs with the suggested window and dual buffers showed improvements in transmittance and efficiency from 22.9％ to 29.3％ and from 4.62％ to 6.41％,respectively,compared to the STSC using a pristine p-a-Si∶H window.