RESUMEN
It is challenging to realize a visible-blind infrared photodetector as the materials that absorb infrared light also absorb visible light. Here, we report the synthesis of IrP2 nanoparticle-embedded few-layer graphene by one-step solid-state pyrolysis and its application in visible-blind infrared sensing. A linear photodetector device was fabricated by drop casting IrP2 nanoparticle-embedded few-layer graphene onto a flexible PET substrate with two gold electrodes separated by â¼16 µm. The photoconductive gain was found to be as high as â¼145% with response and decay times of â¼0.4 and â¼2.8 s, respectively, under 1550 nm irradiation of 800 mW cm-2. The room-temperature responsivity was â¼1.81 A W-1 at 80 mW cm-2 and â¼0.54 A W-1 at a high incident power of â¼2200 mW cm-2 under a bias of 1 V. Interestingly, the device showed response even in the long-wavelength infrared region, but no response was found under visible light. The embedded IrP2 nanoparticles act as trap centers inducing photogating in the device, and the average trap state energy was estimated to be â¼16.5 ± 1.5 meV from the temperature-dependent photocurrent studies. The device was found to be immune to air exposure and bending, suggestive of use a a wearable sensor.