Light Harvesting and Optical-Electronic Properties of Two Quercitin and Rutin Natural Dyes

• Main Authors: Dongpeng Zhao, Qiuchen Lu, Runzhou Su, Yuanzuo Li, Meiyu Zhao
• Format: Article
• Language: English
• Published: MDPI AG 2019-06-01
• Series: Applied Sciences
• Subjects: dye-sensitized solar cell; photoelectrical properties; density functional theory; reorganization energies
• Online Access: https://www.mdpi.com/2076-3417/9/12/2567

The photovoltaic properties of two dyes (quercitin (Q) and rutin (R)) were experimentally investigated. The results showed that Q had excellent photoelectric properties with <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>J</mi> <mrow> <mi>s</mi> <mi>c</mi> </mrow> </msub> </mrow> </semantics> </math> </inline-formula> of 5.480 mA&#183;cm^&#8722;2, <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>V</mi> <mrow> <mi>o</mi> <mi>c</mi> </mrow> </msub> </mrow> </semantics> </math> </inline-formula> of 0.582 V, <inline-formula> <math display="inline"> <semantics> <mrow> <mrow> <mi mathvariant="sans-serif">&#951;</mi> </mrow> </mrow> </semantics> </math> </inline-formula> of 2.151% larger than R with <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>J</mi> <mrow> <mi>s</mi> <mi>c</mi> </mrow> </msub> </mrow> </semantics> </math> </inline-formula> of 1.826 mA&#183;cm^&#8722;2, <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>V</mi> <mrow> <mi>o</mi> <mi>c</mi> </mrow> </msub> </mrow> </semantics> </math> </inline-formula> of 0.547 V, and &#951; of 0.713%. For a better understanding of the photoelectric properties of two molecules and illustrating why the performances of Q is better than R from the micro-level, the UV-VIs spectrum, Fourier transforms infrared (FT-IR) spectrum, and cyclic voltage current characteristics were experimentally investigated. What is more, density functional theory (DFT) and time dependent density functional theory (TD-DFT) have been implemented in theoretical calculation. Based on the calculated results, frontier molecular orbitals (FMOs), charge differential density (CDD), infrared vibration, first hyperpolarizability, projected density orbital analysis (PDOS), electrostatic potential (ESP), and natural bond orbital (NBO) were analyzed. Hole/electron reorganization energies (<inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>&#955;</mi> <mi>h</mi> </msub> <mo>/</mo> <msub> <mi>&#955;</mi> <mi>e</mi> </msub> </mrow> </semantics> </math> </inline-formula>), light harvesting efficiency (LHE), fluorescent lifetime (&#964;), absorption peak, and the vertical dipole moment (<inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>&#956;</mi> <mrow> <mi>n</mi> <mi>o</mi> <mi>r</mi> <mi>m</mi> <mi>a</mi> <mi>l</mi> </mrow> </msub> </mrow> </semantics> </math> </inline-formula>) were calculated, and the shift of conduction band edge of a semiconductor (<i>&#916;E_CB</i>) has been analyzed, which has a close relationship with <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>J</mi> <mrow> <mi>s</mi> <mi>c</mi> </mrow> </msub> </mrow> </semantics> </math> </inline-formula> and <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>V</mi> <mrow> <mi>o</mi> <mi>c</mi> </mrow> </msub> </mrow> </semantics> </math> </inline-formula>. The results demonstrated that, due to the higher LHE, &#964;, <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>&#956;</mi> <mrow> <mi>n</mi> <mi>o</mi> <mi>r</mi> <mi>m</mi> <mi>a</mi> <mi>l</mi> </mrow> </msub> </mrow> </semantics> </math> </inline-formula>, and red-shifted absorption peak, Q has better photoelectric properties than R as a promising sensitizer.