Thermal Annealing Effect on the Conversion Efficiency of Si Solar Cells

Abstract

We investigated the effect of thermal annealing on the performances of Si solar cells. The Si solar cells were fabricated on p-type microtextured Si wafers using a standard cell fabrication process. The fabricated cells were annealed at 250 °C for 60, 80, and 90 min using a halogen lamp heater in N2 ambient. The annealed sample with a time of 60 min showed enhanced optical properties of light absorption, quantum efficiency, and minority carrier lifetime but did not show enhanced cell conversion efficiency. However, while the cell annealed for 90 min showed different optical properties, it showed the highest conversion efficiency of 17.35% compared to the reference cell of 17.14%, indicating the total recovery of the light soaking effect. We further analyzed the hydrogen-related chemical bonding structures for the dopant activation throughout hydrogen diffusion and the electroluminescence by a radiative recombination of a p–n junction.