Structural, optical and photoelectric properties of magnesium phthalocyanine − 1,4-benzenedicarboxylate blend with various thicknesses for photodiode applications

A mixture of magnesium phthalocyanine (MgPc) and 1,4-benzenedicarboxylate (BDC) has been synthesized. Traditional thermal deposition techniques were employed to create thin coatings of the MgPc-BDC blend on glass and FTO substrates. The unique structural properties of this blend were examined using FTIR, AFM, and SEM. SEM image for MgPc-BDC thin film of 50 nm thickness. As depicted in the image, grains with irregular shapes and aggregations are present. AFM analysis of the blend surface showed an average roughness of 89 nm and an average grain size of 128 nm. UV spectrophotometry was used to examine the optical properties of MgPc-BDC, which revealed a decrease of about 7.5% in E_g with the thickness increase. Furthermore, three peaks in the refractive index blend at 450, 610, and 830 nm suggest that the refractive index of the blend varies significantly with the wavelength of light. The carrier concentration (N) and the built-in voltage (V_b) values were thickness-dependent. At an illumination intensity of 90 mW/cm², the photosensitivity of MgPc-BDC increased to 5.31 × 10³. Furthermore, the MgPc-BDC layer displayed excellent charge carrier mobility and effective electron transfer characteristics, reducing charge recombination losses within the device.