Characterization of AlGaN-based metal–semiconductor solar-blind UV photodiodes with IrO2 Schottky contacts

Schalkwyk, L. van; Meyer, W.E.; Auret, F.D.; Nel, Jackie M.; Ngoepe, P.N.M.; Diale, M.

doi:10.1016/j.physb.2011.09.078

Cited by 6 publications

(7 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Comparing the parameters to that of a previous study done by the same authors [3], we found that the average ideality factor degraded by approximately 20% from 1.57 to 1.97, a 3% higher Schottky barrier height from 1.19 eV to 1.22 eV and an 16% increase in series resistance from 100 Ω to 120 Ω. The degradation in ideality factor and higher Schottky barrier height could be a result of the epoxy bonding process, by which some of the epoxy may have made direct contact to the semiconductor material.…”

Section: Electrical Characterizationmentioning

confidence: 86%

“…Each quadrant was characterized with an optoelectronic system [3]. Measurements were made by placing the probes on the chip carrier strips that were epoxy wire bonded to the corresponding contacts.…”

Section: Methodsmentioning

confidence: 99%

“…The PCD at a specified wavelength (J ph (λ s )) was then divided by the illuminated PCD after subtracting the dark PCD at the corresponding wavelengths. The spectral PCD measured in the visible to near-infrared region was done using a 30 W tungstenhalogen lamp mounted directly onto a Czerny-Turner type monochromator [3]. A 400 nm cut-on wavelength order sorting filter was also added to aid in eliminating higher-order diffraction effects.…”

Section: Methodsmentioning

confidence: 99%

“…Solar-blind UV detectors are sensitive only to wavelengths in the UV-C region (200 nm to 280 nm) and therefore only respond to terrestrial sources radiating in this region [3].…”

Section: Introductionmentioning

confidence: 99%

“…We investigated the implementation of an AlGaN-based solar-blind UV four-quadrant detector, after success in studying front illuminated intrinsically solarblind UV AlGaN-based Schottky photodiodes with iridium oxide (IrO 2 ) as the Schottky barrier material, and feasibility of wire bonding with the addition of Au contacts [3].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Implementation of an AlGaN-based solar-blind UV four-quadrant detector

Schalkwyk

Meyer

Nel

et al. 2014

Physica B: Condensed Matter

Self Cite

View full text Add to dashboard Cite

An AlGaN-based front illuminated intrinsically solar-blind ultraviolet four-quadrant Schottky detector was fabricated and characterized. A layered ohmic structure was deposited followed by a multi-step annealing method. Ultraviolet transmissive iridium oxide was used as the Schottky barrier material and formed by a two-step annealing method. Au contacts were deposited on the Schottky contacts and annealed. The detector was mounted onto a commercial chip carrier and wires were epoxy bonded from the ohmic and Au contacts to the carrier strips. The detector had an average ideality factor of 1.97 ± 0.08, a Schottky barrier height of (1.22 ± 0.07) eV, a reverse leakage current density of (2.1 ± 4) nA/cm 2 , a series resistance of (120 ± 30) Ω and a free carrier concentration of (1.6 ± 0.3) × 10 18 cm −3 . Spectral characterization on the photosensitive area of 7.3 × 10 −3 cm 2 yielded a cut-off wavelength at (275 ± 5) nm (4.59 eV to 4.23 eV) for each quadrant, corresponding to the absorption edge of a (46 ± 3)% Al content AlGaN-based material. The detector had an average responsivity of (28 ± 2) mA/W and quantum efficiency of (14 ± 1)% at 250 nm. The ultraviolet-to-visible and near-infrared rejection ratio was between 10 3 and 10 5 for most of the quadrants. Characterization showed uniformity across the quadrants, proving the detector feasible for implementation in future ultraviolet-sensitive electro-optic devices.

show abstract

Section: Electrical Characterizationmentioning

confidence: 86%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…Solar-blind UV detectors are sensitive only to wavelengths in the UV-C region (200 nm to 280 nm) and therefore only respond to terrestrial sources radiating in this region [3].…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations