Hybrid 2D/3D Graphitic Carbon Nitride‐Based High‐Temperature Position‐Sensitive Detector

Ultraviolet position‐sensitive detectors (PSDs) are expected to undergo harsh environments, such as high temperatures, for a wide variety of applications in military, civilian, and aerospace. However, no report on relevant PSDs operating at high temperatures can be found up to now. Herein, we design a new 2D/3D graphitic carbon nitride (g‐C 3 N 4 )/gallium nitride (GaN) hybrid heterojunction to construct the ultraviolet high‐temperature‐resistant PSD. The g‐C 3 N 4 /GaN PSD exhibits a high position sensitivity of 355 mV mm −1 , a rise/fall response time of 1.7/2.3 ms, and a nonlinearity of 0.5% at room temperature. The ultralow formation energy of −0.917 eV atom −1 has been obtained via the thermodynamic phase stability calculations, which endows g‐C 3 N 4 with robust stability against heat. By merits of the strong built‐in electric field of the 2D/3D hybrid heterojunction and robust thermo‐stability of g‐C 3 N 4 , the g‐C 3 N 4 /GaN PSD delivers an excellent position sensitivity and angle detection nonlinearity of 315 mV mm −1 and 1.4%, respectively, with high repeatability at a high temperature up to 700 K, outperforming most of the other counterparts and even commercial silicon‐based devices. This work unveils the high‐temperature PSD, and pioneers a new path to constructing g‐C 3 N 4 ‐based harsh‐environment‐tolerant optoelectronic devices.