High performance conical nanostructured GaN-based photodetectors

Here, we report on a new type of conical nanostructured GaN (CNG), and the corresponding high performance GaN-based metal-semiconductor-metal (MSM) photodetectors (PDs). Compared with the control planar GaN-based MSM PDs, the photocurrent increases by ∼600 times at 0.4 V. The responsivity of the CNG-based PDs can reach ∼2 × 104 A W-1 at 4 V, increased by ∼2000 times compared to the planar GaN-based PDs. The specific detectivity of the CNG-based PDs reaches the maximum at 1 V, ∼1014 Jones, which is more than 800 times to that of the planar GaN-based PDs. Our work paves the way to develop high-performance GaN-based PDs using a new nanostructure for detecting weak optical signals.