Germanium-lead perovskite LEDs reduce toxicity

Metal-halide perovskites are a new class of semiconductor materials for LED display and solar-energy harvesting.

However, the best-performing devices are often made from lead (Pb)-based perovskites, whose toxicity may cause potential environmental concerns. To resolve the toxicity problem, an effective method has been the use of tin (Sn) as a partial or full replacement of lead in the perovskite materials. This strategy has been particularly successful for perovskite solar cells.

However, tin-based (including tin-lead) perovskite materials are generally very poor light emitters, causing unsatisfactory performance of tin-based perovskite light-emitting devices (LEDs).

Recently, a research team led by Prof. Di Dawei from the Zhejiang University College of Optical Science and Engineering discovered that by using germanium (Ge), an environmentally friendly group-IV element, to partially substitute lead in the perovskite, it is possible to create highly luminescent perovskite materials and devices.