Solar-Blind UV PD Based on the BTO/Al_XGa_1-XN Heterostructure for Imaging and Optical Communication

This work demonstrated a solar-blind ultraviolet (UV) photodetector (PD) based on a ferroelectric polarization-engineered BTO/Al<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>X</i></sub>Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>1</roman>-<i>X</i></sub>N heterostructure. The key innovation lied in exploiting BTO’s switchable spontaneous polarization to actively modulate interfacial electrostatics, creating a polarization-coupled carrier transport channel that fundamentally overcame the inherent carrier transport limitations of AlGaN materials. This mechanism synergistically enhanced the built-in electric field and optimized band alignment, which facilitated photogenerated carrier transport. The resultant device achieved high responsivity and detectivity while maintaining intrinsic solar-blind selectivity, significantly surpassing conventional AlGaN-based detectors. Furthermore, we validate its practical utility through UV imaging and accurate optical communication signal decoding, establishing new possibilities for advanced optoelectronic systems.