Electric-Field Distribution Engineering in Multilayer Dielectrics for Low-Voltage Organic Light-Emitting Transistors

Organic light-emitting transistors (OLETs) are promising for next-generation and flexible display technologies, yet their practical application is hindered by the high operating voltages commonly required. Multilayer dielectric architectures have emerged as an effective approach to reducing operating voltage while preserving desirable electrical performance, but a quantitative understanding of electric-field and voltage distribution within such dielectric stacks remains limited. In this work, we systematically investigate electric-field distribution engineering in multilayer dielectrics consisting of an insulating layer, a high-permittivity functional layer, and a polymeric buffering layer. By correlating voltage-partitioning analysis with experimental capacitance measurements, the roles of dielectric constant and layer thickness in governing electric-field distribution, gate coupling efficiency, and leakage behavior are clarified. An optimized dielectric configuration achieves a favorable balance between efficient electric-field utilization and interfacial stabilization. When implemented in organic transistors, the multilayer dielectric enables low-voltage operation. Notably, lateral-channel OLETs incorporating this dielectric stack exhibit electroluminescence at operating voltages as low as 8 V, significantly lower than previously reported horizontal OLET devices. This work provides a general design guideline for achieving low-voltage, high-performance OLET devices through multilayer dielectric architectures.