EFFECTIVE EXCESS CARRIER LIFETIMES EXCEEDING 100 MILLISECONDS INFLOAT ZONE SILICON DETERMINED FROM PHOTOLUMINESCENCE

摘要

Effective excess carrier lifetimes of 130 ms are reported for 1000Ωcm float zone silicon wafers. These values, which are four times larger than the highest effective lifetimes reported for silicon before, are obtained experimentally from transient and from quasi-steady state photoluminescence measurements. It is shown that photoluminescence measurements are a very useful and sensitive technique for determining the effective lifetimeeven at low injection levels. We also show that the lifetimes measured with quasi steady state photoluminescence arenot significantly affected by excess charge that is accumulated in space charge regions, an effect that can lead to adramatic overestimation of the lifetime, when determined by other techniques such as photoconductance.