Mn掺杂Zn-In-S量子点的制备及发光性质研究

制备了Mn掺杂Zn-In-S量子点并研究了Zn/In的量比和反应温度对其发光性质的影响。在Mn掺杂的Zn-In-S量子点的发光谱中观测到一个600 nm发光带。通过改变Zn/In的量比,掺杂量子点的吸收带隙可从3.76 e V(330 nm)调谐到2.82 e V(440 nm),但600 nm发光峰的波长只有略微移动。这些掺杂量子点的最长荧光寿命为2.14 ms。当反应温度从200℃增加到230℃时,掺杂量子点的发光强度增加并达到最大值;而继续升高温度至260℃时,发光强度迅速减弱。此外,测量了Mn掺杂Zn-In-S量子点的变温发光光谱。发现随着温度的升高,发光峰位发生蓝移,发光强度明显下降。分析认为,Mn掺杂Zn-In-S量子点的600 nm发光来自于Mn2+离子的4T1和6A1之间的辐射复合。

Preparation and Photoluminescence Properties of Mn Doped Zn-In-S Quantum Dots

Mn doped Zn-In-S quantum dots (QDs) were prepared and the effect of Zn/In molar ratio and reaction temperature on their photoluminescence properties were studied. A 600 nm photoluminescence band was observed in the doped QDs. The absorption band of the doped QDs could be tuned from 3.76 eV (330 nm) to 2.82 eV (440 nm) by changing the Zn/In ratio while the photoluminescence band around 600 nm only slightly shifted. The longest photoluminescence lifetime in the doped QDs reached up to 2.14 ms. When the reaction temperature increased to 230 ℃ from 200 ℃, the photoluminescence intensity of doped QDs increased and reached the maximum. When the temperature increased to 260 ℃, the photoluminescence intensity rapidly deceased. Further the temperature-dependent photoluminescence spectra of Mn doped Zn-In-S QDs were measured. It was found that the photoluminescence intensity significantly decreased, the photoluminescence peak slightly shifted to higher energy, and the linewidth of the photoluminescence increased with the increasing of temperature. It can be concluded that the emission in Mn doped Zn-In-S QDs originates from the radiative recombination of Mn²⁺ ions between ⁴T₁ and ⁶A₁ energy states.