Investigation on Absorption and Photocurrent in Silicon Absorber with Varied Pyramid Texture Angles by Ray Tracer

Abstract

In this work, ray tracing is used to investigate the effects of pyramid texture angle towards light absorption and photocurrent in 250 μm-thick crystalline silicon (c-Si) absorber. Upright pyramids with texture angles of 10-50o are investigated. Planar c-Si absorber is used as a reference. When the pyramid angle increases, the broadband reflection reduces due to enhanced light scattering which leads to improved light absorption. At angle of 50o, the weighted average reflection (WAR) reduces to 14.7% and broadband light absorption increases. The optical path length enhancement increases to 12 at wavelength of 1100 nm. The reflection and photogenerated current density (Jg) exhibit an inverse relationship with increasing zenith angle. With increasing zenith angle, the reflection from the c-Si absorber increases and this results in lower light absorption and Jg. In the passivated emitter rear cell (PERC) solar cell, the planar solar cell exhibits short-circuit current density (Jsc) of 26 mA/cm2 with conversion efficiency of 13.6%. When both the pyramids and the silicon nitride (SiNx) anti-reflective coating (ARC) are incorporated on the solar cell, the Jsc increases to 39 mA/cm2 and conversion efficiency increases to 20.5%. This is attributed to the enhanced light-trapping and light-coupling effects in the device.