It is described as being "tin-using" which means there could still be lead. Towards the end of the article it even states that a competing panel uses tin-lead which can be described as "tin-using".
[1] is a press release from the original result that has been developed, and specifically refers to replacing lead with tin, with the purported reason to produce a lead-free cell for easier commercialisation (due to the concerns over lead). I chose to share the other link originally because it was newer.
