Sunday, December 20, 2009

Efficient Solution-Processed Photovoltaic Cells Based on an Anthradithiophene/Fullerene Blend


materials systemJsc (mA/cm2)Voc (mV)FFI (mW/cm2)ηP (%)D/Aref
ITO/hexaphenyl-substituted hexabenzocoronene:N,N‘-bis (1-thylpropyl)-3,4,9,10-perylenebis (dicarboximide) (perylene)/Al 0.034 690 0.40 0.47 b 60:40 Schmidt-Mende et al. (10)
ITO/PEDTO:PSS/star-shaped oligothiophene:PCBM/CsF/Al 1.15 850 0.24 80 0.3% 37:63 Roncali et al. (11)
ITO/PEDOT:PSS/X-shaped oligothiophene:PCBM/Al 3.65 850 0.26 100 0.8% 45:55 Sun et al. (12)
ITO/PEDOT:PSS/star-shaped triphenylamine:PCBM/Al 4.10 660 0.30 100 0.8% 25:75 Roquet et al. (13)
ITO/PEDOT:PSS/ethyl-TES-ADT:PCBM/CsF/Al 2.96 840 0.40 100 1% 70:30 this

J. Am. Chem. Soc., 2007, 129 (29), pp 9144–9149

Friday, November 20, 2009

Efficient Squaraine-Based Solution Processable Bulk-Heterojunction Solar Cells




exhibits Jsc = 5.70 mA/cm2, Voc = 0.62 V, fill-factor = 0.35, and power conversion efficiency = 1.24%

J. Am. Chem. Soc., 2008, 130 (52), pp 17640–17641
DOI: 10.1021/ja8067879

Dibenzo[f,h]thieno[3,4-b] quinoxaline-Based Small Molecules for Efficient Bulk-Heterojunction Solar Cells


sampleμe (m2 V−1 s−1)μh (m2 V−1 s−1)VOC (V)JSC (mA cm−2)FFη (%)
1/PCBM50wt%1.61×10−83.14×10−80.902.600.320.75
1/PCBM67wt%2.94×10−81.95×10−80.894.150.461.70

Org. Lett., 2009, 11 (21), pp 4898–4901

Nanoscale Phase Separation and High Photovoltaic Efficiency in Solution-Processed, Small-Molecule Bulk Heterojunction Solar Cells


Blend Ratio--Annealing Temp-------JSC-------- VOC-----FF----- h [%]
60-40--------------110--------------10.0-------- 0.92--- 0.48----4.4

Volume 19 Issue 19, Pages 3063 - 3069


A Low Band Gap, Solution Processable Oligothiophene with a Diketopyrrolopyrrole Core for Use in Organic Solar Cells

J. Phys. Chem. C, 2008, 112 (30), pp 11545–11551

J. Phys. Chem. C, 2008, 112 (39), pp 15543–15552

J. Phys. Chem. C, 2008, 112 (44), pp 17402–17407

Benzothiadiazole-Based Linear and Star Molecules: Design, Synthesis, and Their Application in Bulk Heterojunction Organic Solar Cells


solar cells fabricated with corresponding linear molecules and PC71BM. A power conversion efficiency (PCE) of 1.8%, with Jsc = 4.9 mA/cm2, Voc = 0.92 V, and FF = 0.41 was achieved with one of these star molecules.

Solution-Processable Star-Shaped Photovoltaic Organic Molecule with Triphenylamine Core and Benzothiadiazole−Thiophene Arms



The OSC device based on a blend of S(TPA-BT-4HT) and [70]PCBM (1:3, w/w) exhibited an Isc of 8.58 mA/cm2, a Voc of 0.85 V, and a FF of 32.7%, corresponding to a PCE of 2.39%, under the illumination of AM.1.5, 100 mW/cm2. The Isc of 8.58 mA/cm2 and PSC of 2.39% are among the highest values for the OSCs based on the solution-processable organic molecules reported so far.

Dibenzo[b,def]chrysene Derivatives: Solution-Processable Small Molecules that Deliver High Power-Conversion Efficiencies in Bulk Heterojunction Solar


Table 1. BHJ Solar Cell Parameters for Optimized Thickness and DBC:PCBM Ratios

device

abcd
donor material3332
DBC: PCBM (mg: mg)10:1010:1020:2010:10
solvent (1 mL)PhClCHCl3CHCl3CHCl3
optimum spin speed (rpm)3000400085004500
optimum thickness (nm)150908575
VOC (V)0.260.780.830.91
JSC (mA/cm2)0.0034.736.555.19
fill factor0.280.410.410.47
optimized efficiency, η (%)0.0051.512.252.22


10.1021/cm9028337

Tuesday, January 20, 2009

Amphiphilic Molecular Design as a Rational Strategy for Tailoring Bicontinuous Electron Donor and Acceptor Arrays: Photoconductive Liquid Crystalline


For tailoring solution-processable optoelectronic thin films, a rational strategy with amphiphilic molecular design is proposed. A donor−acceptor dyad consisting of an oligothiophene and C 60, when modified with a hydrophilic wedge on one side and a paraffinic wedge on the other ( 1 Amphi ), forms over a wide temperature range a photoconducting smectic A liquid crystal having bicontinuous arrays of densely packed donor and acceptor units. In contrast, when modified with only paraffinic wedges ( 1 Lipo ), the dyad forms a smectic A liquid crystalline mesophase, which however is poorly conductive. As indicated by an absorption spectral feature along with a synchrotron radiation small-angle X-ray scattering profile, 1 Lipo in the lamellar structure does not adopt a uniform head/tail orientation. Such defective donor and acceptor arrays likely contain a large number of trapping sites, leading to short-lived charge carriers, as observed by a flash photolysis time-resolved microwave conductivity study.

J. Am. Chem. Soc., 2008, 130 (28), pp 8886–8887