No abstract

Três novos pigmentos orgânicos contendo grupamentos carbazol, iminodibenzil e fenotiazina como doadores de elétrons e anéis rodanina bi-ancoradores como receptores de elétrons, foram sintetizados e avaliados como fotossensibilizadores em células solares. Células solares empregando corantes com grupos fenotiazinas como unidades transportadora de buracos e anéis rodanina biancoradores como receptores de elétrons exibiram uma densidade de fotocorrente de curto circuito de 10,6 mA cm -2 , voltagem de circuito aberto de 0,658 V e fator de preenchimento de 0,7, correspondendo a uma eficiência de conversão total de 4,91% sob luz solar padrão AM 1.5.Three new organic dyes comprising carbazole, iminodibenzyl and phenothiazine moieties, as electron donors and di-anchoring rhodanine rings as the electron acceptors, were synthesized and evaluated for use in dye-sensitized solar cells. A solar cell employing dye-containing phenothiazine as a hole-transporting unit and di-anchoring rhodanine rings as the electron acceptors exhibits a short circuit photocurrent density of 10.6 mA cm -2 , an open-circuit voltage of 0.658 V and a fill factor of 0.7, corresponding to an overall conversion efficiency of 4.91% at standard AM 1.5 sunlight.Keywords: dye-sensitized solar cells, electrochemistry, organic dyes, electron donor, rhodanine IntroductionCompounds with extending conjugated p-electron systems are of importance in a wide variety of applications, such as optical, electronic, optoelectronic and magnetic materials. [1][2][3][4][5][6][7] The development of organic electroactive and photoactive materials has progressed significantly in recent years due to their potential applications in optoelectronic devices, such as electroluminescence (EL) devices, photovoltaic devices, thin film transistors and solid-state lasers. 8,9 Donor-acceptor (D-A) organic molecules are one of the most important conjugated organic materials; they have attracted considerable attention as electroluminescent (EL) materials for organic light-emitting diodes (OLEDs) and as photovoltaic materials for organic solar cells. The physical and chemical properties of donoracceptor materials can be modified by selecting suitable donor moieties or/and acceptor moieties.Studies of donor (D)-p (bridge)-acceptor (A) chromophores have found that the intramolecular charge transfer characteristics of these molecules in the excited state are essential for dye sensitizers in dyesensitized solar cells (DSSCs), 10 since the light-induced intramolecular electron transfer can easily occur from the electron donor to the electron acceptor through the p-bridge, which favors photocurrent generation.11 D-A p-conjugated organic dyes have several advantages, such as their ease of synthesis, high molar extinction coefficient, tunable absorption spectral response from the visible to the near infrared (NIR) region, environmental friendliness and inexpensive production techniques compared to those for Ru complexes. In addition, both modeling and experimental results have shown that Wu et al....