We report AlGaN-based back-illuminated solar-blind Schottky-type ultraviolet photodetectors with the cutoff- wavelength from 280nm to 292nm without bias. The devices show low dark current of 2.1× 10^-6A/cm^2 at t...We report AlGaN-based back-illuminated solar-blind Schottky-type ultraviolet photodetectors with the cutoff- wavelength from 280nm to 292nm without bias. The devices show low dark current of 2.1× 10^-6A/cm^2 at the reverse bias of 5 V. The specific detectivity D＊ is estimated to be 3.3 × 10^12cmHz^1/2 W^-1 . To guarantee the performance of the photodetectors, the optimization of AlGaN growth and annealing condition for Schottky contacts were performed. The results show that high-temperature annealing method for Ni/Pt Schottky contacts is effective for the reduction of leakage current.展开更多
Mg-doped AlxGa1-xN epilayers were grown on AlN/sapphire templates by metal organic chemical vapor depo- sition （MOCVD） using an indium-assisted growth method. At room temperature, the resistivity of Mg-doped Alo.43G...Mg-doped AlxGa1-xN epilayers were grown on AlN/sapphire templates by metal organic chemical vapor depo- sition （MOCVD） using an indium-assisted growth method. At room temperature, the resistivity of Mg-doped Alo.43Gao.57N epilayer grown under indium （In） ambient is of the order of 10^4Ω.cm, while the resistivity of Mg-doped Al0.43Ga0.57N grown without In assistance is of the order of 10^6Ω.cm. The ultraviolet light-emitting diodes （UV-LEDs） using the In-assisted Mg-doped Al0.43Ga0.57N as the p-type layers were fabricated to verify the function of indium ambient. It is found that there are a lower turn-on voltage and a lower diode series resistance in the UV-LEDs fabricated with p-type Al0.43Ga0.57 N layers grown under In-ambient.展开更多
基金Supported by the National Science Foundation of China under Grant Nos 60476028, 60325413 and 60776066, the National Basic Research Programme of China under Grant No 2006CB604908, and the Cultivation Fund of the Key Scientific and Technical Innovation Project of the Ministry of Education of China under Grant No 705002.
文摘We report AlGaN-based back-illuminated solar-blind Schottky-type ultraviolet photodetectors with the cutoff- wavelength from 280nm to 292nm without bias. The devices show low dark current of 2.1× 10^-6A/cm^2 at the reverse bias of 5 V. The specific detectivity D＊ is estimated to be 3.3 × 10^12cmHz^1/2 W^-1 . To guarantee the performance of the photodetectors, the optimization of AlGaN growth and annealing condition for Schottky contacts were performed. The results show that high-temperature annealing method for Ni/Pt Schottky contacts is effective for the reduction of leakage current.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60876041, 60577030, 60736033 and 10774001, and the National Basic Research Program of China under Grant Nos 2006CB604908 and 2006CB921607, and the National Key Basic Research Program of China under No TG2007CB307004.
文摘Mg-doped AlxGa1-xN epilayers were grown on AlN/sapphire templates by metal organic chemical vapor depo- sition （MOCVD） using an indium-assisted growth method. At room temperature, the resistivity of Mg-doped Alo.43Gao.57N epilayer grown under indium （In） ambient is of the order of 10^4Ω.cm, while the resistivity of Mg-doped Al0.43Ga0.57N grown without In assistance is of the order of 10^6Ω.cm. The ultraviolet light-emitting diodes （UV-LEDs） using the In-assisted Mg-doped Al0.43Ga0.57N as the p-type layers were fabricated to verify the function of indium ambient. It is found that there are a lower turn-on voltage and a lower diode series resistance in the UV-LEDs fabricated with p-type Al0.43Ga0.57 N layers grown under In-ambient.
