Optical characterization of purple sweet potato (Ipomoea batatas) and carrot (Daucus carota L.) extracts for Dye Sensitized Solar Cell (DSSC) application

Abstract

Abstrak. Penelitian terhadap pewarna alami dari ubi jalar ungu, dan wortel telah dilakukan. Penelitian ini bertujuan untuk mengetahui karakteristik pewarna ubi jalar ungu dan wortel terhadap rentang serapan cahaya matahari. Serapan panjang gelombang pewarna ubi jalar ungu terjadi pada rentang 420–470 nm, energi gap yang diperoleh berdasarkan panjang gelombang maksimum (444 nm) adalah 2.79 eV. Sedangkan pada pewarna wortel dan campuran kedua pewarna (5:5), serapan panjang gelombang terjadi pada rentang yang sama yaitu 400 – 450 nm sehingga energi gap yang diperoleh berdasarkan panjang gelombang maksimum (426 nm dan 424 nm) adalah 2.91 eVdan 2.92 eV. Nilai energi gap yang didapat pada semua sampel relatif besar mengakibatkan tidak maksimalnya nilai arus dan tegangan yang didapat pada pengujian I-V sehingga penentuan efisiensi dan karakteristik DSSC yang diperoleh sulit ditentukan. Abstract. Research on natural dyes from purple sweet potatoes, and carrots has been done. This study aims to determine the characteristics of purple sweet potato and carrot dye on the range of sunlight absorption and functional groups for DSSC applications. Natural dyes from purple sweet potatoes and carrots were extracted using maceration and evaporation methods. Extraction results obtained were then tested for optical properties using a UV-Vis Spectrophotometer and Fourier Transform InfraRed (FTIR). The results showed that the absorption wavelength of purple sweet potato dye occurred in the range of 420–470 nm, the energy gap obtained based on the maximum wavelength (444 nm) was 2.79 eV.. While in carrot dye and a mixture of the two dyes (5:5), the wavelength absorption occurs in the same range, namely 400-450 nm so that the energy gap obtained based on the maximum wavelength (426 nm and 424 nm) is 2.91 eV and 2.92 eV. The energy gap values obtained in all samples are relatively large, resulting in not maximal current and voltage values obtained in the I-V test so that it is difficult to determine the efficiency and characteristics of the DSSC obtained.

Keywords

• purple sweet potato
• carrot
• dye
• optical properties