An automated experiment for determination of thin film semiconductor transport parameters

Thin film semiconductors are more and more the major components of solar devices. Nevertheless, these materials are still the subjects of intense research to improve their properties and reach better cell efficiency. Many experiments have been dedicated to the study of their opto-electronic parameters, most of them using the photoconductivity property of these films. The different techniques use several flux spatial and temporal 'shapes', the light impinging on the sample being uniform or with interferences, steady, modulated or chopped. This is why these different techniques are usually performed with different benches and the state of the sample may change from one bench to the other. In this communication we show that the light 'shape' can be tailored for the needs of several techniques by means of an electrooptic modulator. Therefore, these techniques can be gathered on the same bench, the samples being subsequently studied under the same conditions of vacuum and temperature. We shall show how we have achieved an 'all-in-one' bench and present some experimental results to illustrate all the possibilities of this new bench.