Impact of Surface Texture on Bifacial Silicon Heterojunction Solar Cell Carrier Loss

• Published in: 2021 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) pp. 55 - 56
• Main Authors: Tonita, Erin M., Valdivia, Christopher E., Hinzer, Karin
• Format: Conference Proceeding
• Language: English
• Published: IEEE 13-09-2021
• Subjects: bifacial photovoltaics; Heterojunctions; Lighting; Optical losses; optoelectronic modelling; Photovoltaic cells; recombination; Silicon; silicon heterojunction; surface texture; Surface waves; Three-dimensional displays
• ISSN: 2158-3242
• DOI: 10.1109/NUSOD52207.2021.9541421

We investigate the impact of surface texturing on current loss as a function of depth and wavelength in high efficiency bifacial silicon heterojunction solar cells operating at their maximum power output. We couple 3D ray tracing with TMM thin-film boundary conditions for optical simulations and solve Poisson's drift-diffusion equations to calculate carrier recombination under both front and rear illumination. For front (rear) AM1.5G illumination at normal incidence, regular inverted pyramids out-perform planar surfaces and upright pyramid texture efficiencies by 17.1% rel. (17.9% rel.) and 1.4% rel. (1.0% rel.), respectively. Reduced carrier loss for inverted pyramid textures is calculated to be primarily due to a reflectivity decrease of 63% (76%) compared to planar surfaces which results in enhanced carrier-generation at depths further into the c-Si substrate. The benefit of inverted pyramidal light-trapping will be further enhanced when higher angles of incidence are considered, with angular performance particularly relevant for the rear-side.