Salient features of branched chain amino acid strain states using confocal Raman spectroscopy with adaptive principal component analysis

Casey, Abigail; Dorsey, Carleah; Chusan, Nyia E.; Campbell, Caroline; Triplett, Gregory

doi:10.1016/j.vibspec.2020.103035

Cited by 4 publications

(2 citation statements)

References 26 publications

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“…In other words, PCA transforms large amounts of data into fewer dimensions, which simplifies data visualization and enables additional analysis such as machine learning. In a recent study [24], an adaptation of PCA was coupled with confocal Raman spectroscopy to monitor protein phosphorylation in real time. In particular, this A-PCA approach identified the addition of phosphate groups to amino acid residues and uncovered buried signals in the dense spectral data set.…”

Section: Introductionmentioning

confidence: 99%

Detecting buried silicon interlayers in GaN/diamond bonded structures

Triplett¹,

Graham

Hines

2023

Gallium Nitride Materials and Devices XVIII

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We present a new approach for detecting interlayers in gallium-nitride (GaN) semiconductor structures bonded on single or polycrystalline diamond. GaN-on-diamond is advantageous because it integrates and effective heat spreader into GaN devices, which is important for high power density operation. However, analyzing GaN/diamond interlayers can be difficult because of nonuniformity as well as atomic-scale roughness across the wafer. In this work, we studied GaN/diamond samples using Raman spectroscopy and employed adaptive principal component analysis (PCA) to explore silicon interlayer properties. For each GaN sample bonded to diamond, the presence of a silicon interlayer was confirmed using high resolution scanning transmission electron microscope (HR-STEM) and electron energy loss spectroscopy (EELS). For comparison, we collected Raman spectroscopic data at 25 °C (5 different locations across the wafer, 10 microns apart in each direction) using 10 Raman spectrum acquisitions at each location in the 300-800 /cm range. Raman spectra only show three distinct vibrational modes at ~482 /cm, ~568 /cm and ~735 /cm, associated with the external lamp, GaN E2 (high) and A1 (LO) phonon modes. When spectra were analyzed using adaptive PCA, results reveal buried information in the baseline pertinent to the interlayer, including the ~520 /cm (silicon) phonon mode as well as ~360 /cm, and ~760 /cm modes, owing to nanoscale nonuniformities. Improved analysis of ultra-thin silicon interlayers in GaN/diamond opens up new opportunities to examine the impact of growth/post-growth steps, carrier density, and structure for modeling thermal boundary conductance.

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Section: Introductionmentioning

confidence: 99%

Detecting buried silicon interlayers in GaN/diamond bonded structures

Triplett¹,

Graham

Hines

2023

Gallium Nitride Materials and Devices XVIII

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show abstract

“…However, precisely monitoring signal transduction mechanism remains difficult [ 7 ]. In order to study these processes as they occur, it is critical to leverage and integrate technologies that provide a window of opportunity to record events without inducing any artifacts or changes to the cell's environment [ 8 , 9 ]. A pathway for monitoring these events has been identified, and they include integration of proven technologies that enable the study of biochemical reactions, such as protein phosphorylation [ 10 ].…”

Section: Introductionmentioning

confidence: 99%