Time-resolved spectroscopy of semiconductor materials
Charge carrier dynamics in semiconductors are determined by the architecture and function of the respective device. Thus directly reflecting the nature and quality of wafer materials. Understanding these critical parameters in semiconductor photophysics is of the utmost importance. A precise and efficient measurement of the diffusion lengths of photo-excited electrons and holes is essential for characterizing these systems. Time-resolved photoluminescence quenching experiments are a valuable tool for determining such diffusion lengths.
For specific classes of semiconductors, the characteristic charge carrier lifetime depends strongly on the nature and dimensions of the materials and interfaces involved. Furthermore, surface effects, passivation, energy transfer efficiency of sensitizers as well as the presence of dopants, impurities, and defect sites can also introduce significant variations in the observed lifetimes.
As photoluminescence behavior of a semiconductor is a direct monitor for its charge carrier dynamics, time-resolved photo-luminescence (TRPL) via time-correlated single photon counting (TCSPC) is well suited for analyzing phenomena that influence its dynamics. As a result, the phenomena occurring within a particular system can be characterized directly down to the sub-nanosecond time scale.