Mid-infrared (MIR) light-emitting devices play a key role in optical communications, thermal imaging, and material analysis applications. Two-dimensional (2D) materials offer a promising direction for next-generation MIR devices owing to their exotic optical properties, as well as the ultimate thickness limit. More importantly, van der Waals heterostructures—combining the best of various 2D materials at an artificial atomic level—provide many new possibilities for constructing MIR light-emitting devices of large tuneability and high integration. Here, we introduce a simple but novel van der Waals heterostructure for MIR light-emission applications built from thin-film BP and transition metal dichalcogenides (TMDCs), in which BP acts as an MIR light-emission layer. For BP–WSe₂ heterostructures, an enhancement of ~200% in the photoluminescence intensities in the MIR region is observed, demonstrating highly efficient energy transfer in this heterostructure with type-I band alignment. For BP–MoS₂ heterostructures, a room temperature MIR light-emitting diode (LED) is enabled through the formation of a vertical PN heterojunction at the interface. Our work reveals that the BP–TMDC heterostructure with efficient light emission in the MIR range, either optically or electrically activated, provides a promising platform for infrared light property studies and applications.

中红外 (MIR) 发光器件在光通信、热成像和材料分析应用中发挥着关键作用。二维 (2D) 材料由于其奇异的光学特性以及最终的厚度限制，为下一代中红外设备提供了一个有希望的方向。更重要的是，范德华异质结构——在人工原子水平上结合了各种二维材料中的优点——为构建具有大可调性和高集成度的 MIR 发光器件提供了许多新的可能性。在这里，我们介绍了一种简单但新颖的范德华异质结构，用于由薄膜 BP 和过渡金属二硫属化物 (TMDC) 构建的 MIR 发光应用，其中 BP 充当 MIR 发光层。对于 BP-WSe ₂在异质结构中，观察到中红外区域的光致发光强度提高了约 200%，证明了这种具有 I 型带对齐的异质结构中的高效能量转移。对于 BP-MoS ₂异质结构，通过在界面处形成垂直 PN 异质结，可以实现室温中红外发光二极管 (LED)。我们的工作表明，BP-TMDC 异质结构在 MIR 范围内具有有效的光发射，无论是光激活还是电激活，都为红外光特性研究和应用提供了一个有前景的平台。