The recombination properties of p-type diffusions formed by aluminum diffused into the silicon from an evaporated layer and boron diffused from a B2O3 layer deposited on the silicon from solid doping sources is investigated. The contactless photoconductivity decay method was used to separate the emitter saturation current density Jo of the diffusions themselves from the effect of the diffusion process on the bulk lifetime in the substrate. Al diffusions were found to have very high values of Jo, ranging from approximately 66 × 10-13 A/cm2 at a diffusion temperature of 850°C, to approximately 20 × 10-13 A/cm2 at 1100°C. However, the detrimental effect of these high Jo values on cell efficiency can be managed by reducing the coverage fraction of the diffusions. Bulk lifetimes remained high at approximately 2000 μs after Al diffusion at temperatures from 850°C to 1100°C.