GaN metal-semiconductor-metal (MSM) ultraviolet (UV) photodetectors (PDs) with a low-temperature (LT) Al0.82In0.18N intermediate layer were fabricated and characterized. It was found that we could improve crystalline quality, reduce dark leakage current, enhance UV-to-visible rejection ratio, reduce noise level and achieve a larger detectivity by inserting the lattice-matched AlInN intermediate layer. With -5 V applied, noise equivalent power and detectivity obtained were 1.47 x 10(-13) W and 4.95 x 10(12) cm Hz(0.5) W-1, respectively, for the PDs with the AlInN intermediate layer. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3589302] All rights reserved.