Design of deterministic light-trapping structures for thin silicon heterojunction solar cells.

We optically designed and investigated two deterministic light-trapping concepts named "Hutong" (wafer thickness dependent, patch-like arrangement of "V" grooves with alternating orientations) and "VOSTBAT" (one directional "V" grooves at the front and saw-tooth like structures at the back) for the application in emerging thin silicon heterojunction (SHJ) solar cells. Calculated photocurrent density (Jph) (by weighting the spectrally resolved absorptance with AM1.5g spectrum and integrating over the wavelength) showed that both the Hutong and VOSTBAT structures exceed the Lambertian reference and achieved Jph of 41.72 mA/cm2 and 41.86 mA/cm2, respectively, on 60 µm thin wafers in the case of directional, normal incidence.