A controllable and reversible phase transformation between all-inorganic perovskites for white light emitting diodes

The stable and highly efficient yellow-emitting CsCu(2)I(3)is obtained in a nearly 100% yield based on a controllable and reversible phase transformation between all-inorganic perovskites. This effective strategy is successfully employed to fabricate high-quality electroluminescent white light emitting diodes (WLEDs) for the first time.