Cette étude décrit le principe d'un analyseur de spectre optique entre 2000 Å et 7000 Å, utilisant les propriétés
spécifiques de l'effet photovoltaïque apparaissant dans les structures sandwich de faible épaisseur. La mesure des
longueurs d'onde est liée à la détermination du point de renversement de la tension photovoltaïque en circuit ouvert;
le courant de court-circuit étant par ailleurs proportionnel au flux lumineux. La précision obtenue sur la mesure des
longueurs d'onde dépasse 0,5% si le flux lumineux est supérieur au seuil minimum de 10 μW/cm2.Specific properties of photovoltaïc effects in thin sandwich films have been used to describe a spectral analyser for
optical radiations in the range 2000 Å to 7000 Å. In such structures, we have shown that the photovoltaïc current
has a polarity depending on the wavelength of incident radiation. Further studies relating to conduction and
photoconduction phenomena allow us to attribute the reversal effect to a photoexcitation of ionised traps (Poole
Frenkel effect) or a photoexcitation from valence to conduction band of the photoconductor (Interband
transitions). As these two photoeffects present dimensional dependence, the reversal wavelength λ0 is thickness
dependent. Multilayer dielectric sandwich films may be used as spectral analysers after specific calibration of the
bias voltage, with an accuracy of 0.5% when the intensity of light is greater than 10 μW/cm2.We have obtained some applications of such detectors in the U.V. region, when the dielectric is made from
sputtered zinc sulphide and in the visible region with cadmium sulphide. The specific properties of sputtering
processes are particularly adapted to the introduction of such analysers in microelectronics devices.
