HAZO/AZO structure with improved full spectrum performance for high-efficiency thin-film solar cells

• HAZO/AZO thin films have been prepared by magnetron sputtering.
• Total transmittance shows remarkable absorption reduction at short wavelength.
• Haze factor shows effective light trapping property at full spectrum.
• Electrical properties of textured films are improved.
• A-Si:H, μc-Si:H and triple-junction solar cells are deposited showing its good potential as front contact.

Advanced light management currently plays an important role in high-performance solar cells. In this paper, a HAZO/AZO structure that was produced using RF-magnetron sputtering with segmented hydrogen mediation was proposed to further simultaneously enhance the transmittance and light trapping capability at full solar spectrum. Compared to the standard AZO front contact, the total transmittance at short wavelength and haze at full spectrum were remarkably enhanced by 5.1% and 20.7%, respectively. Additionally, the resistivity of the HAZO/AZO structure was enhanced by 16.9%. When applied as front electrodes, the spectral response of a-Si:H and μc-Si:H solar cells increased. The quantum efficiency of the a-Si:H solar cell improved by 7.9% (from 59% to 66.9%) at 400 nm. An initial efficiency of 8.69% with Jsc over 27 mA/cm2 was obtained for the μc-Si:H solar cell. Finally, an a-Si:H/a-SiGe:H/μc-Si:H triple-junction solar cell was obtained with the initial efficiency over 15%, which illustrates a promising and potentially cost-effective alternative structure to further improve the high-quality transparent electrodes for high-efficiency thin-film solar cells.

Optical properties of etched AZO, HAZO and HAZO/AZO films total transmittance (Ttot) (b) haze factor (HT)Figure optionsDownload as PowerPoint slide