• n+ laser doping demonstrated from POx/Al2O3 passivation stacks on silicon. • Metallised J0 of 540 fA cm−2 for n+ laser-doped region with Rsheet of 39.5 Ω/□. • Consistent with values for POCl3 furnace diffusions, indicating minimal defects. • Same POx/Al2O3 stack provides J0 of 2.5 fA cm−2 on undiffused planar surfaces. • 23.6% simulated efficiency for laser-doped n-type PERL cell based on POx/Al2O3.

We demonstrate how perovskite hysteresis can result in permanent reductions in power output in perovskite/silicon tandem modules—including irreversible hotspot-induced damage—from only brief periods of shading.

In this work, we find that the crystallization of ALD TiOx is very sensitive to the film’s thickness, where a small increase in TiOx thickness can trigger a phase change from amorphous TiOx into anatase, which causes a significant increase in J0s. More importantly, we demonstrate that the incorporation of Al ions into the TiOx films inhibits crystallization, which in turn retains excellent passivation for thicker TiOx.