IQE (AIM: IQE) is a British semiconductor company founded 1988 in Cardiff, Wales, which manufactures advanced epitaxial wafers for a wide range of technology applications for wireless, optoelectronic, electronic and solar devices. IQE specialises in advanced silicon and compound semiconductor materials based on gallium arsenide (GaAs), indium phosphide (InP), gallium nitride (GaN) and silicon. The company is the largest independent outsource producer of epiwafers manufactured by metalorganic vapour phase epitaxy (MOCVD), molecular beam epitaxy (MBE) and chemical vapor deposition (CVD).The company is headquartered with two manufacturing facilities in Cardiff, with factories in Newport and Milton Keynes in the United Kingdom; Bethlehem, Pennsylvania, Taunton, Massachusetts, and Greensboro, North Carolina, in the United States, and Taiwan and Singapore in Asia.
Abstract We report wafer scale characterisation of O-band 150 mm InAs quantum dot edge-emitting lasers, using on-wafer measurements of etched-facet lasers. Threshold current, lasing wavelength, and spontaneous emission spectra were mapped across the wafer and compared with post-growth photoluminescence (PL) peak emission wavelength and full-width half-maximum (FWHM) to evaluate device performance and uniformity. Strong correlation is observed between the post-growth PL data and the on-wafer laser characteristics. Pearson correlation coefficients of 0.93 were calculated between both PL peak emission wavelength and peak lasing wavelength, and PL peak emission wavelength and peak spontaneous emission wavelength. A coefficient of 0.56 was found between PL FWHM and threshold current. Together, these indicate excellent fabrication uniformity and demonstrate that device performance is strongly correlated with variations in the epitaxial growth. The PL peak emission wavelength and FWHM were 1281.70 nm and 57.90 nm with standard deviations of 1.00 nm and 1.62 nm, respectively. The low fabrication variability enables a lasing yield of 98.2 % (of lasers with thresholds below the maximum current used during characterisation of 1.5 A) for a population of 1152 devices with a 2000 µm cavity length. By combining on-wafer etched-facet measurements with post singulation measurements on both cleaved-facet lasers alongside gain and absorption measurements from the segmented-contact method, the etched-facet reflectivity at 6 mm from the wafers centre was extracted to be 0.074 ± 0.003. Additional investigation indicates that the sub-optimal etched-facet reflectivity is likely due to off-vertical angled facets, measured at 81.8 ∘ relative to the wafer surface, which increases mirror losses, raising the threshold current and reducing yield for shorter cavity devices due to the higher gain requirement. Overall, the spatial uniformity of the facet reflectivity demonstrates that on-wafer etched-facet test structures provide a robust platform for diagnosing epitaxial and fabrication variations without the need for extensive wafer cleaving.
Recent advancements in quantum cascade lasers (QCLs) grown on silicon substrates have showcased the potential of this technology in realizing cost-effective integrated infrared photonics platforms. Epitaxial-material characterization data from the demonstrated lasers operating in the mid-wave and long-wave infrared spectral regions and its analysis are presented in this work. The analysis indicates that reducing defect density in the active region to below 2 x 10(7)/cm(-2) is essential for achieving performance comparable to high-performance QCLs grown on native InP substrates. The data also suggest that defect density can be reduced by employing either lattice-matched designs or strain-balanced designs with a low-strain both in quantum wells and barriers and by reducing number of active region stages in the laser core.
AlxIn1-xAsySb1-y is a promising multiplier for avalanche photodiodes (APD) on InP for near-infrared applications. In this work, we investigated the potential of two different ternary-containing layer stacks for the growth of AlInAsSb digital alloys on InP and InP-on-Si templates with applications in future photodetectors. STEM measurements confirmed high-quality material and interfaces on both substrates with no evidence of phase separation. Low dark currents and high gains were measured from PIN diodes grown on both substrates, with slightly higher dark currents observed in the Si-based device due to defects resulting from lattice mismatch in the template. (c) 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement
Natural fish ladders – a new habitat for the otter? // In this research project, the occurrence of the Eurasian otter (Lutra lutra L.) at near-natural fish pass facilities in seven Bavarian streams was investigated. These facilities play a crucial role as migration corridors and habitats for fish at transverse structures and weirs (barriers). By using molecular genetic analysis of collected otter scat, 33 individuals were identified at 12 fish passes. The results also indicate that primarily family groups inhabit these fish passes and use them intensively. Kinship analyses suggest that otters are spreading between Lower Bavaria and Upper Bavaria along the Danube and Inn rivers. The impact of otter use of fish pass facilities on fish populations should be addressed in future studies.
Après la formation du Service de la faune en 1961, des chercheurs de l’État québécois tentent de faire de l’écologie scientifique la pierre angulaire de l’exploitation des ressources cynégétiques. La démocratisation de la chasse sportive offre aux chercheurs l’occasion d’imprimer leur marque sur les politiques de gestion de la faune terrestre. Les chercheurs produisent des études qui rendent visibles les populations d’orignaux et de cerfs de Virginie, des espèces fauniques prisées par les chasseurs sportifs. Dès lors, l’intégration des préceptes de l’écologie scientifique se manifeste dans les travaux sur la quantification des populations d’ongulés et sur la délimitation de leurs milieux de vie. Cela dit, l’écologisation de la gestion faunique demeure un processus constamment redéfini, comme en témoignent les circonstances qui entourent l’intégration des préceptes de l’écologie scientifique à la réglementation et aux pratiques d’aménagement et de gestion de la faune au Québec.
