The effects of dopant content and calcination temperature on Mn-doped TiO2-ZrO2 structure and properties were successfully investigated. Composite of Mn-doped titania-zirconia was synthesized by sol-gel method. Titanium(IV) isopropoxide was used as the precursor of TiO2, while zirconiapowder was used as another semiconductor. MnCl2∙4H2O was used as the source of dopant in this study. Various amounts of manganese were incorporated into TiO2-ZrO2 and calcination was performed at temperatures of 500, 700 and 900 °C. Synthesized composites were characterized by Fourier-transform infrared spectroscopy (FTIR), specular reflectance UV-Vis spectroscopy (SR UV-Vis), X-ray diffraction method (XRD) and scanning electron microscopy equipped with X-ray energy dispersive spectroscopy (SEM-EDX). The results showed that Mn-doped TiO2-ZrO2 with the lowest bandgap (2.78 eV) was achieved with 5% of Mn dopant and calcined at 900 °C, while Mn-doped TiO2-ZrO2 with the highest bandgap (3.12 eV) was achieved with 1% of Mn dopant content calcined at 500 °C.

The theoretical study of the use of cyano acid derivatives as electron acceptor groups in pelargonidin as a dye compound in sensitized solar cells (DSSC) was successfully carried out. Theoretical study was carried out with the purpose to determine the effect modification of the addition of cyanoacrylic benzothiadiazole, cyanoacrylate, cyanovinyl, and cyanocynamic as electron acceptors to the characteristics of pelargonidin as dye DSSC. The effect of modification is based on the parameters of bond length, spectra, molecular electron density, light harvesting efficiency (LHE), (VRP), and HOMO-LUMO energy. The molecular structure created using the Avogadro program, then optimized by DFT/TDDFT method using a base set 6.311G *. Based on the results of research on pelargonidin-benzothiadiazole cyanoacrylate is a better modification when compared with pelargonidin without modification or pelargonidin modified with other cyano acids. This modification is better modification based on parameters molecular electron density, HOMO-LUMO energy, (VRP), bond lengths, and spectra. Pelargonidin-benzothiadiazole cyanoacrylic electron density in LUMO conditions centred in benzothiadiazole cyanoacrylic, HOMO and LUMO energy of dye is -4.97856 eV & -2,56731 eV, VRP value 0.439, bond lengths 1.936 A, and spectra at wavelength 393-14 nm & 377-09 nm. Based on the light harvesting efficiency (LHE), pelargonidin without modification is the best modification with an LHE value 0.820.Kajian teoritis penggunaan turunan asam siano sebagai gugus akseptor elektron pada pelargonidin sebagai senyawa pewarna sel surya tersensitasi (DSSC) telah berhasil dilakukan. Kajian teoritis dilakukan dengan tujuan untuk mengetahui pengaruh modifikasi penambahan gugus asam benzatiadizol sianoakrilik, sianoakrilik, sianovinil, dan sianosinamik sebagai akseptor elektron terhadap karakteristik pelargonidin sebagai dye pada DSSC. Pengaruh modisfikasi didasarkan pada parameter panjang ikatan, spektra, kerapatan elektron molekul, efisiensi penyerapan cahaya (LHE), konstanta kopling (VRP), dan energi HOMO-LUMO. Struktur molekul dibuat dengan menggunakan program Avogadro, kemudian dioptimasi dengan metode DFT/TDDFT menggunakan basis set 6.311G*. Berdasarkan hasil penilitian pelargonidin-benzatiadizol sianoakrilik merupakan modifikasi yang lebih baik apabila dibandingkan dengan pelargonidin tanpa modifikasi maupun pelargonidin yang dimodifikasi dengan asam siano lain. Hal tersebut didasarkan pada parameter posisi kerapatan elektron molekul, energi HOMO-LUMO, konstanta kopling (VRP),