Multiplet Theory for Conduction Band Edge and O-Vacancy Defect States in SiO2, Si3N4, and Si Oxynitride Alloy Thin Films

ABSTRACTWe report the determination of the distribution of occupied defect states in hydrogenated amorphous silicon from the deconvolution of constant photocurrent measurement (CPM) spectra, and the modelling of the distribution with the defect pool.The CPM spectra were taken on undoped a-Si:H samples either in their as-grown state, in the annealed state, after quenching from high temperature, or after light-soaking. The spectra were deconvoluted to account for transitions from deep levels and from valence band tail states to a conduction band assumed to have a sharp edge. As-grown or annealed-state samples show a peak at 1.0 eV (0.2 eV FWHM) below the conduction band edge. Assuming a mobility gap of 1.9 eV, this peak lies 0.9 eV above the valence band edge. We ascribe this peak to the Do/+ transition. CPM spectra of light-soaked and thermally quenched samples show shifts in the peak position and increases in die peak height in accordance with the defect pool model. The model calculations agree with the CPM results, so that the applicability of CPM spectral analysis to obtaining detailed values of defect pool parameters is demonstrated.

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Characterization of conduction band edge discontinuity for InAlAs/GaAsSb using InP/GaAsSb heterojunction bipolar transistors

physica status solidi (a) ◽

10.1002/pssa.201127699 ◽

2012 ◽

Vol 209 (8) ◽

pp. 1579-1582

Author(s):

C. W. Ng ◽

H. Wang

Keyword(s):

Conduction Band ◽

Heterojunction Bipolar Transistors ◽

Bipolar Transistors ◽

Band Edge ◽

Conduction Band Edge

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Conduction Band Edge Energy Profile Probed by Hall Offset Voltage in InGaZnO Thin Films

Micromachines ◽

10.3390/mi11090822 ◽

2020 ◽

Vol 11 (9) ◽

pp. 822

Author(s):

Hyo-Jun Joo ◽

Dae-Hwan Kim ◽

Hyun-Seok Cha ◽

Sang-Hun Song

Keyword(s):

Magnetic Field ◽

Electron Density ◽

Conduction Band ◽

Electron System ◽

Band Edge ◽

Conduction Band Edge ◽

Offset Voltage ◽

Three Samples ◽

Dimensional Electron System ◽

Longitudinal Distance

We measured and analyzed the Hall offset voltages in InGaZnO thin-film transistors. The Hall offset voltages were found to decrease monotonously as the electron densities increased. We attributed the magnitude of the offset voltage to the misalignment in the longitudinal distance between the probing points and the electron density to Fermi energy of the two-dimensional electron system, which was verified by the coincidence of the Hall voltage with the perpendicular magnetic field in the tilted magnetic field. From these results, we deduced the combined conduction band edge energy profiles from the Hall offset voltages with the electron density variations for three samples with different threshold voltages. The extracted combined conduction band edge varied by a few tens of meV over a longitudinal distance of a few tenths of µm. This result is in good agreement with the value obtained from the analysis of percolation conduction.

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