High-responsivity vertical-illumination Si/Ge uni-traveling-carrier photodiodes based on silicon-on-insulator substrate

Si/Ge uni-traveling carrier photodiodes exhibit higher output current when space-charge effects are overcome and thermal effects are suppressed, which is highly beneficial for increasing the dynamic range of various microwave photonic systems and simplifying high-bit-rate digital receivers in different applications. From the point of view of packaging, detectors with vertical-illumination configuration can be easily handled by pick-and-place tools and are a popular choice for making photo-receiver modules. However, vertical-illumination Si/Ge uni-traveling carrier (UTC) devices suffer from inter-constraint between high speed and high responsivity. Here, we report a high responsivity vertical-illumination Si/Ge UTC photodiode based on a silicon-on-insulator substrate. The maximum absorption efficiency of the devices was 2.4 times greater than the silicon substrate owing to constructive interference. The Si/Ge UTC photodiode was successfully fabricated and had a dominant responsivity at 1550 nm of 0.18 A/W, a 50% improvement even with a 25% thinner Ge absorption layer.Comment: 5pages,2figure

cis-Bis[2-(1,3-benzothia­zol-2-yl)-1-(4-fluoro­phen­yl)ethen­yl](pentane-2,4-dionato-κ2 O,O′)iridium(III)

In the title compound, [Ir(C15H9FNS)2(C5H7O2)], the Ir atom is hexa­coordinated by three chelating ligands, with two cyclo­metalated 2-(1,3-benzothia­zol-2-yl)-1-(4-fluoro­phen­yl)ethenyl ligands showing N,C-bidentate coordination and an O,O′-bidenate pentane-2,4-dionate anion, thereby forming a distorted octa­hedral enviroment

4-[4,5-Bis(pyridin-2-yl)-1H-imidazol-2-yl]phenol monohydrate

In the title hydrate, C19H14N4O·H2O, the dihedral angle between the two pyridine rings is 38.0 (2)°. The dihedral angle between the imidazole and benzene rings is 25.3 (2)°. The crystal structure is stabilized by inter­molecular O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds