A comparison between quasi-steady state and transient photoconductance lifetimes in silicon ingots: simulations and measurements

• Published in: 2017 IEEE 44th Photovoltaic Specialist Conference (PVSC) pp. 2707 - 2710
• Main Authors: Goodarzi, Mohsen, Sinton, Ronald, Chung, Daniel, Mitchell, Bernhard, Trupke, Thorsten, Macdonald, Daniel
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01-06-2017
• Subjects: Carrier lifetime; Charge carrier density; Charge carrier lifetime; Mathematical model; QSSPC; Silicon; Silicon ingot; Sun; Surface recombination; Time measurement; Transient analysis; Transient lifetime
• DOI: 10.1109/PVSC.2017.8366658

We present and compare numerical simulations and experimental data for Quasi-Steady State (QSS) and transient photoconductance lifetime measurements on silicon ingots. The simulation results show that the QSS method is generally more accurate for lifetimes below 150 μs, whereas transient measurements are more accurate above this value. However, transient measurements require sufficient time to have elapsed after the flash is terminated, to ensure that the impact of the unpassivated ingot surface is reduced. The results also show that the surface recombination velocity has a slightly reduced impact on n-type material in comparison with p-type material, due to the reduced minority carrier mobility. The simulation results are also compared with measured QSS and transient lifetimes on a standard p-type monocrystalline block.