Changes of the occupied density of defect states of a-Si:H upon illumination

Ristein J, Ley L (1996)

Publication Type: Journal article

Publication year: 1996

Journal

Physical Review B American Physical Society

Publisher: American Physical Society

Book Volume: 53

Pages Range: 4522

Journal Issue: 8

Abstract

We study the light-induced transient changes of the near surface density of occupied states g(E) of undoped and boron-doped a-Si:H with photomodulated total photoelectron yield spectroscopy. The data show an increase of g(E) upon illumination between 0.35 eV above E F and 0.7 eV below E F (towards the valence band) and a decrease in the region of deep valence-band-tail states. The difference signal depends sublinearly on the laser intensity and reaches a maximum of Δg ≈ 10 17 cm -3 eV -1 at a laser intensity of 30 mW cm -2 (λ=532 nm). Time-resolved measurements reveal rise and decay times of the order of milliseconds. The experimental results are explained quantitatively by a recombination model. In the framework of this model, a range of deep defects around mid-gap energy are singly occupied and neutral at probe-light intensities. Additional illumination with a laser leads to double occupation of these defects and a decrease of the valence-band-tail occupation.

Authors with CRIS profile

Jürgen Ristein Lehrstuhl für Laserphysik Lothar Ley Naturwissenschaftliche Fakultät

How to cite

APA:

Ristein, J., & Ley, L. (1996). Changes of the occupied density of defect states of a-Si:H upon illumination. Physical Review B, 53(8), 4522.

MLA:

Ristein, Jürgen, and Lothar Ley. "Changes of the occupied density of defect states of a-Si:H upon illumination." Physical Review B 53.8 (1996): 4522.

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