High-performance 4H-SiC-based ultraviolet p-i-n photodetector

Abstract

A high-performance 4H-SiC p-i-n photodetector for visible-blind ultraviolet (UV) applications has been designed and fabricated. The electrical and optical characteristics were measured at room temperature. The photodetector suffered from significant dark current of 2.5 pA/mm2 at reverse bias of 5 V, and the UV light photocurrent was larger than four orders of magnitude higher than the dark current. The built-in potential and the unintentional i-layer doping concentration were obtained from capacitance-voltage (C-V) measurements. The spectral peak responsivity of the detector reached 0.13 A/W at a wavelength of 270 nm, corresponding to a maximum external quantum efficiency of ∼61%. And the ratio of responsivity at 270 nm to that at 380 nm was >103. The characteristics imply that the photodetector has a great improved ultraviolet-visible rejection ratio which is needed for ultraviolet signal detection.

Annealing effects on the optical and structural properties of Al2O3/SiO2 films as UV antireflection coatings on 4H-SiC substrates

“…The 4H-SiC p-i-n photodetectors [4] were found to have the peak responsivity of 0.13 A/W and the maximum external quantum efficiency (QE) of 61% at the wavelength of 270 nm. The Ni/4H-SiC Schottky photodiodes were reported [2] to have the external QE higher than 50% from 230 to 295 nm and get the peak of 65% at 275 nm, corresponding to an internal QE close to 100%.…”

“…Silicon carbide (SiC)-based ultraviolet (UV) photodetectors such as Schottky barrier [1,2], metal-semiconductor-metal (MSM) [3], p-i-n [4] and avalanche [5,6] have been presenting considerable potential for UV detection in flame detection, ozone-hole sensing, short-range communication, etc. The 4H-SiC p-i-n photodetectors [4] were found to have the peak responsivity of 0.13 A/W and the maximum external quantum efficiency (QE) of 61% at the wavelength of 270 nm.…”

“…Therefore, we deposited Al 2 O 3 /SiO 2 double-layer UV antireflection coatings on 4H-SiC substrates by electron-beam evaporation for the purpose of improving the external QE of 4H-SiC-based UV photodetectors. As annealing is an important postprocessing for forming high quality Schottky and ohmic contacts [2,4] on 4H-SiC substrates, it is significant to examine the optical and structural properties of the Al 2 O 3 /SiO 2 films annealed at various temperatures.…”

Formation of SiC thin films by chemical vapor deposition with vinylsilane precursor

“…SiC is an attractive material for metal surface coatings, 1,2) photoelectrodes, 3) solar cells, 4) ultraviolet photodetectors, 5) power devices, 6,7) and other devices because it has excellent material properties such as a large energy band gap, a high chemical stability, a high robustness, a high thermal conductivity, and conductivity controllability through impurity doping. 8) These properties of SiC thin films are also preferable for the application of electrode coatings to water electrolysis technology.…”

An ultraviolet photodetector with an active layer composed of solution processed polyfluorene:Zn0.71Cd0.29S hybrid nanomaterials

“…The photoresponsivity values reported in this study are either comparable or higher than that of GaN (230 mA/W at 356 nm) [35] and SiC (130 mA/W at 270 nm) based UV-PDs [36] and has potential applications in environmental and biological monitoring. Contrary to the approaches followed in literature which explain mechanism in polymer:QD blends, i.e.…”