MoSe₂–WSe₂ heterostructures host strongly bound interlayer excitons (IXs), which exhibit bright photoluminescence (PL) when the twist angle is near 0° or 60°. Over the past several years, there have been numerous reports on the optical response of these heterostructures but no unifying model to understand the dynamics of IXs and their temperature dependence. Here we perform a comprehensive study of the temperature, excitation power, and time-dependent PL of IXs. We observe a significant decrease in PL intensity above a transition temperature that we attribute to a transition from localized to delocalized IXs. Astoundingly, we find a simple inverse relationship between the IX PL energy and the transition temperature, which exhibits opposite power-dependent behaviors for near 0° and 60° samples. We conclude that this temperature dependence is a result of IX–IX exchange interactions, whose effect is suppressed by the moiré potential trapping IXs at low temperature.

MoSe ₂ –WSe ₂异质结构承载强结合的层间激子 (IX)，当扭转角接近 0° 或 60° 时，其表现出明亮的光致发光 (PL)。在过去的几年里，有许多关于这些异质结构的光学响应的​​报告，但没有统一的模型来理解 IX 的动力学及其温度依赖性。在这里，我们对 IX 的温度、激发功率和时间相关的 PL 进行了全面研究。我们观察到 PL 强度在高于转变温度时显着降低，我们将其归因于从局部到离域 IX 的转变。令人震惊的是，我们发现 IX PL 能量和转变温度之间存在简单的反比关系，这在接近 0° 和 60° 的样品中表现出相反的功率相关行为。