SPV signal analysis: fits and simulations

We are currently developing simulation tools to enable first principle calculations of the electronic structure in a given photoactive material or material combination, based on solid-state physics.

The SPS/SPV simulation tool enables users of any SPS/SPV equipment to verify their measurements against simulated scenarios. Thereby for instance reducing development time for new materials research and/or testing the tolerances of a given photoactive material configuration.

All transient responses can be fitted between 10 ns and 100 ms using the build-in stretched exponentials multi-parameter fit function with three basic parameters; t_I, β_i and A_i, where t is the transient time constant, β is the stretching factor to the exponential function and A is the signal amplitude. The multi-parameter i can in most cases be limited to 2 (i.e. i = 1,2), 5 is rare, but sometime needed for complex structures. In principle, fitting with i = 1,….,12 is possible. 

Figure 1 shows an example using SPV for the radial characterization of shallow defects close to the conduction band in a float zone silicon wafer using a fit function consisting of the sum of 5 stretched exponential functions.