2D Material light–emitting transistor with a dynamically controllable emission location for optimized waveguide coupling on silicon

Two-dimensional semiconductors are promising for silicon-compatible on-chip light sources. However, substantial challenges persist regarding component performance, functional integration, and the lack of optimal system architectures. Specifically, the precise integration of nanoscale light sources with photonic components, such as waveguides, remains difficult because of stringent alignment requirements. Here, we demonstrate a silicon-compatible MoTe 2 light-emitting transistor (LET) featuring both electrical switching and dynamically reconfigurable light emission. The device operates as an ambipolar transistor with a high on/off ratio (>10 5 ) and uses a voltage-tunable dynamic p-i-n junction, enabling electrically programmable electroluminescence (EL) positioning across the 15-micrometer channel. We further integrate the LET with a silicon waveguide acting as a back gate. The emission around 1300 nanometers is dynamically tuned and coupled into the waveguide, collected via grating couplers. We achieve an electrically reconfigurable EL localization in silicon-integrated devices and a record efficiency of 67%. This work enables the development of reconfigurable photonic circuits by overcoming integration bottlenecks.