Loading…
Direct monitoring of minority carrier density during light induced degradation in Czochralski silicon by photoluminescence imaging
In this paper, we present a new method for studying the light induced degradation process, in which the minority carrier density is monitored directly during light soaking by photoluminescence imaging. We show experimentally that above a certain minority carrier concentration limit, Δnlim, the boron...
Saved in:
Published in: | Journal of applied physics 2013-05, Vol.113 (19) |
---|---|
Main Authors: | , , |
Format: | Article |
Language: | English |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | In this paper, we present a new method for studying the light induced degradation process, in which the minority carrier density is monitored directly during light soaking by photoluminescence imaging. We show experimentally that above a certain minority carrier concentration limit, Δnlim, the boron oxygen (B-O) defect generation rate is fully independent of the injected carrier concentration. By simulation, we determine Δnlim for a range of p-type Czochralski silicon samples with different boron concentrations. The normalized defect concentrations, Nt*, are determined for the same samples by time-resolved Quasi Steady State Photoconductance measurements. After 10 min of light degradation, no correlation between Δnlim, and Nt* is observed. These results indicate that the role of the excess carriers during the rapid decay is to first change the charge state of the defects by shifting the electron quasi-Fermi level across the energy level of the defect centre in its passive state (Elat = EV + (635 ± 18) meV) and that, subsequently, another rate-determining step proceeds before the defect centre becomes recombination active. |
---|---|
ISSN: | 0021-8979 1089-7550 |
DOI: | 10.1063/1.4806999 |