Heterojunction solar cells with 23% efficiency on n-type epitaxial kerfless silicon wafers

We present a heterojunction (HJ) solar cell on n‐type epitaxially grown kerfless crystalline‐silicon with an in‐house‐measured conversion efficiency of 23%. The total cell area is 243.4 cm2. The cell has a short‐circuit current density of 39.6 mA cm−2, an open‐circuit voltage of 725 mV, and a fill factor of 0.799. The effect of stacking faults (SFs) is examined by current density (J) mapping measurements as well as by spectral response mapping. The J mapping images show that the localized lower J regions of the HJ solar cells are associated with recombination sites originating from SFs, independent of whether SFs are formed on the emitter or absorber side. The solar cell results and our analysis suggest that epitaxially grown wafers based on kerfless technology could be an alternative for low‐cost industrial production of Si HJ solar cells. Copyright © 2016 John Wiley & Sons, Ltd. Silicon heterojunction solar cells consist of epitaxially grown crystalline silicon wafers coated with hydrogenated amorphous silicon layers for passivating contact formation. Here, we demonstrate a conversion cell efficiency of 23% in size of 243.4 cm2 by using epitaxial silicon wafers with low stacking fault density and a rear‐emitter structure. The solar cell results and our analysis suggest that epitaxially grown wafers based on kerfless technology could be an alternative for low‐cost industrial production of silicon heterojunction solar cells.