Defects characterization in thin films photovoltaics materials by correlated high-frequency modulated and time resolved photoluminescence: An application to Cu(In,Ga)Se_2

摘要

We develop a contactless method based on photoluminescence measurements in the modulated mode: the high-frequency modulated photoluminescence. The high frequency domain allows accessing to carrier dynamics in the nanosecond time scale which is typical for thin films materials. To illustrate the experimental method, we analyze Cu(In, Ga)Se-2 photovoltaic absorbers where recombination mechanisms in the bulk, surface and grain boundaries are not completely understood. We correlate the data with classical time resolved photoluminescence. We show that the combination of the two methods allows, with the help of one dimensional simulations, an estimation of carrier traps and recombination centers parameters in thin films samples.