Analysis of Energy Gap and The Refractive Index of Barium Strontium Titanate (Ba0.2Sr0.8TiO3) Films doped of Chlorophyll from Green Leafy Vegetables

Abstract

Ferroelectric films has superior optoelectronic properties and widely applied as a base of electronic components such as light sensors. Improvement the performance of the light sensor can be obtained by adding dopant materials to thin film. In recent years, organic materials as a dopant materials have been extensively used, one of them is chlorophyll. Ba0.2Sr0.8TiO3 without (0%) and with a (2.5%) dopant cassava, mustard greens, papaya, and spinach leaves chlorophyll extracts prepared on silicon substrate (100). The Ba0.2Sr0.8TiO3 film growth process using chemical solution deposition method with spin coating technique of 8,000 rpm for 30 seconds in solubility 0.2 M. The Barium Strontium Titanate film was annealing at 850°C for 8 hours with an increase of 1.7°C/min. The results of the reflectance data processing from the UV-Vis spectrophotometer characterization showed that the Ba0.2Sr0.8TiO3 without chlorophyll has energy gap 3.25 eV at wavelength 580 nm with refractive index 1.46. Energy gap of Ba0.2Sr0.8TiO3 with dopant of cassava, mustard greens, papaya, and spinach in a row are 3.24 eV, 3.22 eV, 3.00 eV, and 3,22 eV at the wavelength are 570 nm, 565 nm, 640 nm, and 570 nm with refractive index 1.3, 1.27, 1.34, and 1.24. It can be concluded that Ba0.2Sr0.8TiO3 without chlorophyll is sensitive to the orange color spectrum, Ba0.2Sr0.8TiO3 with the cassava and mustard green chlorophyll are sensitive to the green spectrum, and Ba0.2Sr0.8TiO3 with papaya chlorophyll is sensitive to the red spectrum.