AlGaN Ultraviolet Metal–Semiconductor–Metal Photodetectors with Reduced Graphene Oxide Contacts

AlGaN semiconductors are promising materials in the field of ultraviolet (UV) detection. We fabricated AlGaN/GaN UV metal–semiconductor–metal (MSM) photodiodes with two back-to-back interdigitated finger electrodes comprising reduced graphene oxide (rGO). The rGO showed high transparency below the wavelength of 380 nm, which is necessary for a visible-blind photodetector, and showed outstanding Schottky behavior on AlGaN. As the photocurrent, dark current, photoresponsivity, detectivity, and cut-off wavelength were investigated with the rGO/AlGaN MSM photodiodes with various Al mole fractions, systematic variations in the device characteristics with the Al mole fraction were confirmed, proving the potential utility of the device architecture combining two-dimensional materials, rGO, and nitride semiconductors.

A novel cobalt ion implanted pyridylporphyrin/graphene oxide assembly for enhanced photocatalytic hydrogen production

By facilely pre-implanting Co[Formula: see text] ions in the graphene oxide, a novel 5,15-diphenyl-10,20-di(4-pyridyl)porphyrin pillared graphene oxide was fabricated by means of electrostatic interaction and coordination interaction. It was shown that the morphology and the structure of graphene oxide and pyridylporphyrin nanocomposite were modified by introducing Co[Formula: see text] ions on the interface between graphene oxide and pyridylporphyrin. Furthermore, it was found that the photocatalytic hydrogen evolution activity over the Co[Formula: see text] ions implanted in the graphene oxide and pyridylporphyrin nanocomposite was evidently higher than in the graphene oxide and pyridylporphyrin nanocomposite without Co[Formula: see text]. This confirmed that strong interaction and efficient electron transfer between pyridylporphyrin and graphene oxide are the important reasons for the enhanced photocatalytic activity for hydrogen evolution. Subsequently, this technique will be a simple and efficient approach to optimize the transfer pathway of photogenerated electrons and to improve photocatalytic performance by implanting metal ions in the interface of nanocomposites.