Studying charge carrier dynamics in solar cell materials is important to characterize their effectiveness. For example, the charge carrier lifetime of a semiconductor material is related to the efficiency of a solar cell. Terahertz spectroscopy is a common way to track the charge carrier dynamics as it computes the amount of terahertz signal absorbed by the charge carriers. Here, we explore different pump-probe measurement techniques using terahertz spectroscopy using a replaceable diode laser. A replaceable diode laser allows the pump-probe measurement setup to analyze the charge carrier dynamics using different light wavelengths. Using interchangeable optical wavelengths, we can further analyze different depths of the materials and conduct real-life sunlight conditions in the experiment. We demonstrated that two pump-probe measurement techniques, the steady-state and the pulsed excitation setup, could be used to measure the charge carrier lifetime. Not only that, the steady-state setup could be used to analyze the charge carrier mobility. While there is a discrepancy in the lifetime result between the two setups, the experimental data and simulations show the discrepancy can be resolved by increasing the excitation duration of the steady-state setup. Furthermore, we explore different ways to improve the accuracy of these setups in the future.
"},{"label":"Degree","value":["Bachelor of Arts with Departmental Honors"]},{"label":"Author-supplied Keywords","value":["Charge carrier lifetime","Solar cell","Terahertz spectroscopy"]},{"label":"Administrative Note","value":"Drupal Node ID: 33823