AlxGa1-xN-based back-illuminated solar-blind photodetectors with external quantum efficiency of 89%

E. Cicek, Ryan P McClintock, C. Y. Cho, B. Rahnema, Manijeh Razeghi*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

79 Scopus citations

Abstract

We report on high performance AlxGa1-xN-based solar-blind ultraviolet photodetector (PD) array grown on sapphire substrate. First, high quality, crack-free AlN template layer is grown via metalorganic chemical vapor deposition. Then, we systematically optimized the device design and material doping through the growth and processing of multiple devices. After optimization, uniform and solar-blind operation is observed throughout the array; at the peak detection wavelength of 275 nm, 729 μm2 area PD showed unbiased peak external quantum efficiency and responsivity of ∼80% and ∼176 mA/W, respectively, increasing to 89% under 5 V of reverse bias. Taking the reflection loses into consideration, the internal quantum efficiency of these optimized PD can be estimated to be as high as ∼98%. The visible rejection ratio measured to be more than six orders of magnitude. Electrical measurements yielded a low-dark current density: <2 × 10-9 A/cm2, at 10 V of reverse bias.

Original languageEnglish (US)
Article number191108
JournalApplied Physics Letters
Volume103
Issue number19
DOIs
StatePublished - Nov 4 2013

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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