Submicron Thickness Characterization of poly-Si thin films on Textured Surfaces by X-ray Diffraction for Minimizing Parasitic Absorption in Poly-Si/SiO2 Passivating Contact Cells

Poly-Si/SiO2 passivating contacts have shown great potential for industry-relevant next-generation solar cells. Previous work has demonstrated an improved Jsc from dry reactive ion etching in an SF6 environment, using front metal grids as a self-aligned mask. Here, we show an effective method to measure the front poly-Si thickness on an alkaline textured surface using X-ray diffraction. The calculated thicknesses are compared with cross-section SEM analysis and Quokka simulation. We show that by thinning the front poly-Si from 200 nm to 60 nm, Jsc increases by 2.4 mA/cm2, leading to an absolute efficiency gain of 1.73%. Finally, we discuss possible reasons for the premature loss of passivation before the removal of all poly-Si.

National Renewable Energy Laboratory (NREL), Colorado School of Mines

Kejun Chen and Vincenzo Lasalvia and William Nemeth and San Theingi and Harvey Guthrey and Matthew B. Hartenstein and Abhijit S. Kale and Matthew Page and Alex Bothwell and James Sites and Paul Stradins and Sumit Agarwal and David L. Young

Quokka simulation,XRD,cross-sectional scanning electron microscopy,light beam induced current,parasitic absorption,passivating contacts,silicon solar cell

2020

6

10.1109/PVSC45281.2020.9300794

9781728161150

01608371

Conference Record of the IEEE Photovoltaic Specialists Conference

2783-2785

Institute of Electrical and Electronics Engineers Inc.

2020-June