P-type silicon wafers are expected to dominate commercial manufacturing for many years.However,the trend towards lower cost p-type multi wafers appears in contradiction to device design trends where the inclusion of high efficiency attributes such as rear surface passivation,selective emitters,low area contacts etc can only be justified when used with high quality wafers.The incompatibility appears to be exacerbated by recent reports of significant light-induced degradation (LID) in such wafers.However the apparent contradiction may in part be addressed by new hydrogen-passivation technology that involves the control of the charge state of the hydrogen atoms within the silicon to greatly enhance their diffusivity and reactivity and therefore their ability to passivate defects and recombination.Such passivation has demonstrated large improvements in quality in all p-type wafer types including UMG silicon.Many of the worlds largest PV cell and wafer manufacturers and tool manufacturers are collaborating in the development,evaluation and commercialization of this technology.