Achieving Tunable Cold/Warm White-Light Emission in a Single Perovskite Material with Near-Unity Photoluminescence Quantum Yield

Abstract Single materials that exhibit efficient and stable white-light emission are highly desirable for lighting applications. This paper reports a novel zero-dimensional perovskite, Rb 4 CdCl 6 :Sn 2 + , Mn 2 + , which demonstrates exceptional white-light properties including adjustable correlated color temperature, high color rendering index of up to 85, and near-unity photoluminescence quantum yield of 99%. Using a co-doping strategy involving Sn 2+ and Mn 2+ , cyan-orange dual-band emission with complementary spectral ranges is activated by the self-trapped excitons and d-d transitions of the Sn 2+ and Mn 2+ centers in the Rb 4 CdCl 6 host, respectively. Intriguingly, although Mn 2+ ions doped in Rb 4 CdCl 6 are difficult to excite, efficient Mn 2+ emission can be realized through an ultra-high-efficient energy transfer between Sn 2+ and Mn 2+ via the formation of adjacent exchange-coupled Sn–Mn pairs. Benefiting from this efficient Dexter energy transfer process, the dual emission shares the same optimal excitation wavelengths of the Sn 2+ centers and suppresses the non-radiative vibration relaxation significantly. Moreover, the relative intensities of the dual-emission components can be modulated flexibly by adjusting the fraction of the Sn 2+ ions to the Sn–Mn pairs. This co-doping approach involving short-range energy transfer represents a promising avenue for achieving high-quality white light within a single material.