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Optimization of an Electron Transport Layer to Enhance the Power Conversion Efficiency of Flexible Inverted Organic Solar Cells.

Lee KH, Kumar B, Park HJ, Kim SW - Nanoscale Res Lett (2010)

Bottom Line: ZnO seed layers were deposited using spin coating at 3,000 rpm for 30 s onto indium tin oxide (ITO)-coated polyethersulphone (PES) substrates.The ZnO NRs were grown using an aqueous solution method at a low temperature (90°C).The optimized device with ZnO NRs exhibited a threefold increase in PV performance compared with that of a device consisting of a ZnO seed layer without ZnO NRs.

View Article: PubMed Central - HTML - PubMed

ABSTRACT
The photovoltaic (PV) performance of flexible inverted organic solar cells (IOSCs) with an active layer consisting of a blend of poly(3-hexylthiophene) and [6, 6]-phenyl C(61)-butlyric acid methyl ester was investigated by varying the thicknesses of ZnO seed layers and introducing ZnO nanorods (NRs). A ZnO seed layer or ZnO NRs grown on the seed layer were used as an electron transport layer and pathway to optimize PV performance. ZnO seed layers were deposited using spin coating at 3,000 rpm for 30 s onto indium tin oxide (ITO)-coated polyethersulphone (PES) substrates. The ZnO NRs were grown using an aqueous solution method at a low temperature (90°C). The optimized device with ZnO NRs exhibited a threefold increase in PV performance compared with that of a device consisting of a ZnO seed layer without ZnO NRs. Flexible IOSCs fabricated using ZnO NRs with improved PV performance may pave the way for the development of PV devices with larger interface areas for effective exciton dissociation and continuous carrier transport paths.

No MeSH data available.


Related in: MedlinePlus

Current density voltage (J–V) characteristic for solar cells under AM 1.5 G simulated solar illumination
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Figure 3: Current density voltage (J–V) characteristic for solar cells under AM 1.5 G simulated solar illumination

Mentions: Fig. 3 shows the current density–voltage (J–V) characteristics for the solar cells fabricated with/without ZnO NRs by varying the ZnO seed layer thickness. Measurements were carried out under solar-simulated AM 1.5 G illumination with a 100 mW/cm2 light source. The Jsc, Voc, FF, and PCE derived from J–V curves are summarized in Table 1. We found that PV performance improved as seed layer thickness increased for the IOSCs fabricated with the ZnO seed layer, up to an optimum thickness of 130 nm. In IOSC structures, the electron transport layer is affected by injection of holes from the highest occupied molecular orbital (HOMO) level of P3HT—4.8 eV to ITO—4.8 eV [16]. Therefore, to prevent contact between the active layer and the ITO electrode, the ZnO seed layer should exist as a stable compact film. However, the ZnO seed layer was a porous film consisting of nanoparticles and could not completely prevent contact between the organic active layer and the ITO electrode until it reached an optimized thickness. On the other hand, resistance of the seed layer increased with increasing thickness. As a result, the Jsc of the device increased up to the optimum film thickness, after which it began to decrease due to a larger series resistance, as shown in Fig. 3. Consequently, the PV performance of the device varied in the same way. Thus, an optimization process was necessary with respect to the thickness of the electron transport layer in order to prevent contact between the active layer and the ITO electrode with the lowest series resistance. We optimized the seed layer thickness to 130 nm, which allowed for the extraction of the maximum efficiency from the device. Furthermore, we studied the PV performances of IOSCs fabricated with a ZnO seed layer and with a ZnO NRs/ZnO seed layer.


Optimization of an Electron Transport Layer to Enhance the Power Conversion Efficiency of Flexible Inverted Organic Solar Cells.

Lee KH, Kumar B, Park HJ, Kim SW - Nanoscale Res Lett (2010)

Current density voltage (J–V) characteristic for solar cells under AM 1.5 G simulated solar illumination
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2991231&req=5

Figure 3: Current density voltage (J–V) characteristic for solar cells under AM 1.5 G simulated solar illumination
Mentions: Fig. 3 shows the current density–voltage (J–V) characteristics for the solar cells fabricated with/without ZnO NRs by varying the ZnO seed layer thickness. Measurements were carried out under solar-simulated AM 1.5 G illumination with a 100 mW/cm2 light source. The Jsc, Voc, FF, and PCE derived from J–V curves are summarized in Table 1. We found that PV performance improved as seed layer thickness increased for the IOSCs fabricated with the ZnO seed layer, up to an optimum thickness of 130 nm. In IOSC structures, the electron transport layer is affected by injection of holes from the highest occupied molecular orbital (HOMO) level of P3HT—4.8 eV to ITO—4.8 eV [16]. Therefore, to prevent contact between the active layer and the ITO electrode, the ZnO seed layer should exist as a stable compact film. However, the ZnO seed layer was a porous film consisting of nanoparticles and could not completely prevent contact between the organic active layer and the ITO electrode until it reached an optimized thickness. On the other hand, resistance of the seed layer increased with increasing thickness. As a result, the Jsc of the device increased up to the optimum film thickness, after which it began to decrease due to a larger series resistance, as shown in Fig. 3. Consequently, the PV performance of the device varied in the same way. Thus, an optimization process was necessary with respect to the thickness of the electron transport layer in order to prevent contact between the active layer and the ITO electrode with the lowest series resistance. We optimized the seed layer thickness to 130 nm, which allowed for the extraction of the maximum efficiency from the device. Furthermore, we studied the PV performances of IOSCs fabricated with a ZnO seed layer and with a ZnO NRs/ZnO seed layer.

Bottom Line: ZnO seed layers were deposited using spin coating at 3,000 rpm for 30 s onto indium tin oxide (ITO)-coated polyethersulphone (PES) substrates.The ZnO NRs were grown using an aqueous solution method at a low temperature (90°C).The optimized device with ZnO NRs exhibited a threefold increase in PV performance compared with that of a device consisting of a ZnO seed layer without ZnO NRs.

View Article: PubMed Central - HTML - PubMed

ABSTRACT
The photovoltaic (PV) performance of flexible inverted organic solar cells (IOSCs) with an active layer consisting of a blend of poly(3-hexylthiophene) and [6, 6]-phenyl C(61)-butlyric acid methyl ester was investigated by varying the thicknesses of ZnO seed layers and introducing ZnO nanorods (NRs). A ZnO seed layer or ZnO NRs grown on the seed layer were used as an electron transport layer and pathway to optimize PV performance. ZnO seed layers were deposited using spin coating at 3,000 rpm for 30 s onto indium tin oxide (ITO)-coated polyethersulphone (PES) substrates. The ZnO NRs were grown using an aqueous solution method at a low temperature (90°C). The optimized device with ZnO NRs exhibited a threefold increase in PV performance compared with that of a device consisting of a ZnO seed layer without ZnO NRs. Flexible IOSCs fabricated using ZnO NRs with improved PV performance may pave the way for the development of PV devices with larger interface areas for effective exciton dissociation and continuous carrier transport paths.

No MeSH data available.


Related in: MedlinePlus