Abstract
In this study, the new isatin hydrazone derivative (IL) and its ZnO-complex (ZnOIL) were synthesized to be employed in solar energy conversion applications. The structural characterizations of IL and ZnOIL were carried out by energy-dispersive X-ray spectroscopy, UV-Vis spectroscopy, mass spectrometry, and nuclear magnetic resonance. Au/IL(200 nm)/p-Si and Au/ZnOIL(200 nm)/p-Si heterojunctions were fabricated using the thermal evaporation method. Comparative studies have been made between photoresponse performance of Au/IL/p-Si and Au/ZnOIL/p-Si heterojunctions using impedance spectroscopy analysis under the same environmental conditions. Bode and Nyquist plots of both devices were investigated in dark and under different illuminations (0 - 160 Klux). Furthermore, the dielectric functions and the electric modulus were determined under different illuminations and frequencies. The behavior of electrical conductivity was examined under various illumination conditions. The results showed that the IL ligand and its ZnOIL complex possess an excellent photoresponse and semiconducting properties. The fabricated device based on ZnOIL complex (Au/ZnOIL/p-Si) exhibits better photoresponse performance and electrical characteristics than that one based on IL ligand (Au/IL/p-Si). ZnO chelated IL as a new method to form ZnOIL in photovoltaic devices, promoted their photoelectrical properties , which enhance their photoresponse performance. Thereby the synthesized ZnOIL could be used as a potential material to improve the performance of solar energy conversion devices.