5855-26-5Relevant articles and documents
Co-sensitization of organic dyes for efficient dye-sensitized solar cells
Cheng, Ming,Yang, Xichuan,Li, Jiajia,Zhang, Fuguo,Sun, Licheng
, p. 70 - 77 (2013/03/13)
Novel cyanine dyes, in which a tetrahydroquinoline derivative is used as an electron donor and 1-butyl-5-carboxy-3, 3-dimethyl-indol-1-ium moiety is used as an electron acceptor and anchoring group, were designed and synthesized for application in dye-sensitized solar cells. The photovoltaic performance of these solar cells depends markedly on the molecular structure of the dyes in terms of the n-hexyl chains and the methoxyl unit. Retardation of charge recombination caused by the introduction of n-hexyl chains resulted in an increase in electron lifetime. As a consequence, an improvement of open-circuit photovoltage (V oc) was achieved. Also, the electron injection efficiencies were improved by the introduction of methoxyl moiety, which led to a higher short-circuit photocurrent density (Jsc). The highest average efficiency of the sensitized devices (η) was 5.6 % (Jsc=13.3 mA cm-2, Voc=606 mV, and fill factor FF=69.1 %) under 100 mW cm-2 (AM 1.5G) solar irradiation. All of these dyes have very high absorption extinction coefficients and strong absorption in a relatively narrow spectrum range (500-650 nm), so one of our organic dyes was explored as a sensitizer in co-sensitized solar cells in combination with the other two other existing organic dyes. Interestingly, a considerably improved photovoltaic performance of 8.2 % (Jsc=20.1 mA cm-2, Voc=597 mV, and FF=68.3 %) was achieved and the device showed a panchromatic response with a high incident photon-to-current conversion efficiency exceeding 85 % in the range of 400-700 nm. Sensitive dyes absorb it all: Co-sensitization of three spectrally complementary dyes on a TiO2 film in a well-designed sequence significantly improves the photovoltaic performance of the device, and an efficiency of 8.2 % is achieved. The devices demonstrate a panchromatic response with an incident photon-to-current conversion efficiency >80 % over the entire visible spectral region from 400 to 700 nm. Copyright
Dye-sensitized solar cells based on a donor-acceptor system with a pyridine cation as an electron-withdrawing anchoring group
Cheng, Ming,Yang, Xichuan,Li, Jiajia,Chen, Cheng,Zhao, Jianghua,Wang, Yu,Sun, Licheng
, p. 16196 - 16202 (2013/02/23)
New hemicyanine dyes (CM101, CM102, CM103, and CM104) in which tetrahydroquinoline derivatives are used as electron donors and N-(carboxymethyl)-pyridinium is used as an electron acceptor and anchoring group were designed and synthesized for dye-sensitized solar cells (DSSCs). Compared with corresponding dyes that have cyanoacetic acid as the acceptor, N-(carboxymethyl)-pyridinium has a stronger electron-withdrawing ability, which causes the absorption maximum of dyes to be redshifted. The photovoltaic performance of the DSSCs based on dyes CM101-CM104 markedly depends on the molecular structures of the dyes in terms of the n-hexyl chains and methoxyl. The device sensitized by dye CM104 achieved the best conversion efficiency of 7.0 % (Jsc=13.4 mA cm-2, Voc=704 mV, FF=74.8 %) under AM 1.5 irradiation (100 mW cm-2). In contrast, the device sensitized by reference dye CMR104 with the same donor but the cyanoacetic acid as the acceptor gave an efficiency of 3.4 % (Jsc=6.2 mA cm -2, Voc=730 mV, FF=74.8 %). Under the same conditions, the cell fabricated with N719 sensitized porous TiO2 exhibited an efficiency of 7.9 % (Jsc=15.4 mA cm-2, Voc=723 mV, FF=72.3 %). The dyes CM101-CM104 show a broader spectral response compared with the reference dyes CMR101-CMR104 and have high IPCE exceeding 90 % from 450 to 580 nm. Considering the reflection of sunlight, the photoelectric conversion efficiency could be almost 100 % during this region.
