Interlaboratory comparison of InGaAsP EX-SITU characterization
Alexana Roshko, Kristine A. Bertness
A study to improve the accuracy of ex-situ characterization of InGaAsP materials for optoelectronics is underway. Six InGaAsP thin film specimens, with nominal photoluminescence wavelengths of 1.1, 1.3 and 1.5 mm, have been measured, with X-ray diffraction and photoluminescence (PL), sequentially by different laboratories. X-ray measurement reproducibility appears to be dominated by specimen nonuniformity. Typical standard deviations in x-ray rocking curve peak splittings as measured by the different laboratories are from 1 to 11 arcsec, while the lateral variations across specimens are between 9 and 150 arcsec. In contrast, the variation among PL measurements is larger than the variation within individual samples, allowing the difference between measurements to be assessed. Offsets of measurements from some instruments were observed. But these had no apparent correlation with factors, such as pump wavelength, wavelength calibration, sample temperature, pump power density, and peak identification, as reported by the different laboratories. Analysis of the raw PL data with identical methods revealed that the variations are intrinsic to the data, not artifacts of the methods used to extract a characteristic energy from the PL spectra.
and Bertness, K.
Interlaboratory comparison of InGaAsP EX-SITU characterization, Journal of Crystal Growth, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=30739
(Accessed November 30, 2023)