In this work, undoped and Mn doped Pb(Zn1/3Nb2/3)O3-4.5PbTiO3 nanoparticles were dispersed in biopolymer and in mixed biopolymer + pentacene as active layer and deposited by spin coating on ITO glasses. Morphological, optical and electrical properties of these layers were investigated. SEM images show the superposition of different deposited layers ITO/TiO2/PZN-PT-np-biopolymer on glass substrate with thicknesses of 1.600 μm, 1.505 μm and 1.765 μm respectively. The absorbance value in UV visible for pentacene layer increases from 75 % to 99 % while the transmittance for ITO glasses diminishes from more than 80 % to 2 %. Optical gaps of ITO, TiO2, PZN-PT nanoparticles are respectively 3.75 eV, 3.2 eV and 3.15 eV. Pentacene deposition reduced the gap to 1.65 eV for undoped sample and 1.60 eV for the doped ones. Intermediate gaps (2.3 eV and 2.6 eV for undoped sample and 2.15 eV and 2.7 eV for doped sample) were observed. Photoluminescence performed between 450 nm and 750 nm confirms « these intermediate gaps ».