Vertically stacked van der Waals heterostructures constitute a promising platform for providing tailored band alignment with enhanced excitonic systems. Here, we report observations of neutral and charged interlayer excitons in trilayer WSe₂–MoSe₂–WSe₂ van der Waals heterostructures and their dynamics. The addition of a WSe₂ layer in the trilayer leads to significantly higher photoluminescence quantum yields and tunable spectral resonance compared to its bilayer heterostructures at cryogenic temperatures. The observed enhancement in the photoluminescence quantum yield is due to significantly larger electron–hole overlap and higher light absorbance in the trilayer heterostructure, supported via first-principles pseudopotential calculations based on spin-polarized density functional theory. We further uncover the temperature- and power-dependence, as well as time-resolved photoluminescence of the trilayer heterostructure interlayer neutral excitons and trions. Our study elucidates the prospects of manipulating light emission from interlayer excitons and designing atomic heterostructures from first-principles for optoelectronics.

垂直堆叠的范德华异质结构构成了一个有前途的平台，可通过增强的激子系统提供定制的能带对准。在这里，我们报告了三层WSe ₂ -MoSe ₂ -WSe ₂ van der Waals异质结构及其动力学的中性和带电层间激子的观察结果。WSe _2的添加与在低温下的双层异质结构相比，该三层中的三氧化二铝层可导致更高的光致发光量子产率和可调谐的光谱共振。观察到的光致发光量子产率的提高归因于三层异质结构中更大的电子-空穴重叠和更高的吸光度，这是通过基于自旋极化密度泛函理论的第一性原理pseudo势计算得到支持的。我们进一步揭示了三层异质结构层间中性激子和三重子的温度和功率依赖性以及时间分辨的光致发光。我们的研究阐明了操纵层间激子发光并从光电子第一原理设计原子异质结构的前景。