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.