OPTICAL, ELECTRICAL AND PHOTOELECTRICAL PROPERTIES OF QUERCETIN-CO(II) COMPLEX/N-SI ORGANIC-INORGANIC HYBRID DEVICE

Abstract

Quercetin is a member of the flavonoid’s class and colorful organic molecule widely distributed in nature. Quercetin is known as 2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one with molecular formula C15H10O7. Also, quercetin has conjugated structure with 16 π-rich electrons. In this study, Quercetin cobalt (II) complex (Quercetin-Co(II) Complex) was synthesized. The thin films of synthesized quercetin cobalt (II) complex were formed on glass and semiconductor substrates by sol-gel spin coating technique. The absorption, reflection and transmittance spectra of the thin film were taken in 200-1100 nm wavelength range. The optical band gap of the film was determined from absorption studies and was found to be 2.59 eV for direct transitions and 1.90 eV for indirect transitions. The morphological properties of the thin film formed on the semiconductor substrates was analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). We fabricated Au/Quercetin-Co(II) Complex/n-Si organic-inorganic hybrid device to investigate electrical and photoelectrical properties. The current-voltage (I-V) measurement of the device was carried out at room temperature and in dark. The device has a rectification behavior with the ideality factor n of 1.55 and the barrier height ϕb of 0.77 eV. In addition, the short circuit current (Isc) and open circuit voltage (Voc) have been extracted from the I-V measurements under 100 mW/cm2 illumination conditions. Besides, the capacitance-voltage (C-V) characteristics of the device at different frequency and room temperature are discussed.