Structural, electronic and photovoltaic characterization of multiwalled carbon nanotubes grown directly on stainless steel

• Luca Camilli,
• Manuela Scarselli,
• Silvano Del Gobbo,
• Paola Castrucci,
• Eric Gautron and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2012, 3, 360–367, doi:10.3762/bjnano.3.42

• highly oriented pyrolytic graphite (HOPG). Notably, a broadening of the π-plasmon peak in the case of MWCNTs is evident. In addition, a photocurrent was measured when MWCNTs were airbrushed onto a silicon substrate. External quantum efficiency (EQE) and photocurrent values were reported both in planar

• and in top-down geometry of the device. Marked differences in the line shapes and intensities were found for the two configurations, suggesting that two different mechanisms of photocurrent generation and charge collection are in operation. From this comparison, we are able to conclude that the

• geometry gives a photocurrent intensity and an external quantum efficiency (EQE) value much higher than those measured in the in-plane configuration. Results and Discussion In Figure 1 the chemical vapour deposition chamber used to grow the CNTs is displayed. The stainless-steel substrate is mounted on a

Ultraviolet photodetection of flexible ZnO nanowire sheets in polydimethylsiloxane polymer

• Jinzhang Liu,
• Nunzio Motta and
• Soonil Lee

Beilstein J. Nanotechnol. 2012, 3, 353–359, doi:10.3762/bjnano.3.41

• device with Ag electrodes. Previously, we studied the UV photoconduction of ZnO nanowire films with different PL properties, i.e., defect contents. The UV photocurrent of those ZnO nanowire films (2 mm wide and 10 mm long) with vacuum deposited Ag electrodes was in the range of 13–90 μA at 8 V when

• measured in air [10]. In this work, the UV photocurrent of the device with Ag paste electrodes, embedded in PDMS, exceeds 400 μA at 8 V. Even at a reverse bias of −8 V, the current is 160 μA, much higher than that of the device without PDMS. In the dark, the current values of the device in PDMS are 110 nA

• nanowire film can be enhanced by PDMS coating. The responsivity of the device, defined as the photocurrent per unit of incident optical power, is determined by the UV photoconductivity of the ZnO nanowires. From the I–V curves we can deduce that the PDMS coating over ZnO nanowires results in an

Junction formation of Cu₃BiS₃ investigated by Kelvin probe force microscopy and surface photovoltage measurements

• Fredy Mesa,
• William Chamorro,
• William Vallejo,
• Robert Baier,
• Thomas Dittrich,
• Alexander Grimm,
• Martha C. Lux-Steiner and
• Sascha Sadewasser

Beilstein J. Nanotechnol. 2012, 3, 277–284, doi:10.3762/bjnano.3.31

• frequency. For the Cu3BiS3 sample signatures of the three relatively broad, deep defect levels were observed at all frequencies. We remark that dips in the amplitude spectra could appear, for example, when the sign of SPV signals changed. For better interpretation a correlation of SPV with photocurrent

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

• of a modified C60 [87]. An agreement between the measured photocurrent action spectrum and the absorption spectrum of the modified fullerene served as an indication that the photoactive species was the modified fullerene. A photon-to-current conversion efficiency as high as 15% was measured

• force may compensate to some extent for the lack of chemical bonding between the quantum dots and the terminating groups of the monolayer, thus, enabling the high photocurrent response measured for this system. Another study on charge transport between SAMs and TiO2 was based on a mixed-monolayer

Highly efficient ZnO/Au Schottky barrier dye-sensitized solar cells: Role of gold nanoparticles on the charge-transfer process

• Tanujjal Bora,
• Htet H. Kyaw,
• Soumik Sarkar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2011, 2, 681–690, doi:10.3762/bjnano.2.73

• barrier at the ZnO/Au interface and not due to the faster electron injection from dye to ZnO. The effect of Au nanoparticles on the generation of photocurrent in the ZnO/Au-nanocomposite-based DSSC was studied for small- (0.1 cm2) as well as large-area (1 cm2) solar cells and the results are compared to

• sensitizer dye molecules, the photoexcited electrons in the Au nanoparticles are transferred to the conduction band (CB) of ZnO, and then diffuse through the ZnO nanorods towards the conducting fluorine-doped tin oxide (FTO) substrate resulting in higher photocurrent and photovoltage, as observed. The

• illumination; the results are shown in Table 2. In Figure 3a, the best J–V characteristics obtained for both bare ZnO-nanorod and ZnO/Au-nanocomposite DSSCs are shown. It was found that the photocurrent of the ZnO-nanorod DSSC improved upon the incorporation of Au nanoparticles in the ZnO-nanorod

Simple theoretical analysis of the photoemission from quantum confined effective mass superlattices of optoelectronic materials

• Debashis De,
• Sitangshu Bhattacharya,
• S. M. Adhikari,
• A. Kumar,
• P. K. Bose and
• K. P. Ghatak

Beilstein J. Nanotechnol. 2011, 2, 339–362, doi:10.3762/bjnano.2.40

• photo-emitted current density from the said SLs as a function of normalized electron degeneracy, normalized intensity, wavelength and thickness, respectively, for all the cases of Figure 1. Using Equation 15 and Equation 16, the normalized photocurrent from QWW effective mass HgTe/Hg1−xCdxTe SL, whose

• normalized photoemission from QWW effective mass HgTe/Hg1−xCdxTe and InxGa1−xAs/InP SLs decreases with increasing thickness and exhibits large oscillations. From Figure 7, it appears that the normalized photocurrent for the said system increases with increasing carrier concentration, exhibiting a quantum

• jump for a particular value of the said variable, for all the models of both the SLs. From Figure 8 and Figure 9, it can be inferred that the normalized photocurrent in this case increases with decreasing intensity and wavelength in different manners. From Figure 10, it has been observed that the

Schottky junction/ohmic contact behavior of a nanoporous TiO₂ thin film photoanode in contact with redox electrolyte solutions

• Masao Kaneko,
• Hirohito Ueno and
• Junichi Nemoto

Beilstein J. Nanotechnol. 2011, 2, 127–134, doi:10.3762/bjnano.2.15

• redox waves in the dark due to the [Fe(CN)6]4−/3− couple. Further studies showed that multiple Schottky junctions/ohmic contact behavior inducing simultaneously both photocurrent and overlapped reversible redox waves was found in the CV of a nanoporous TiO2 photoanode soaked in an aqueous redox

• electrolyte solution containing methanol and [Fe(CN)6]4−. That is, the TiO2 nanosurface responds to [Fe(CN)6]4− to give ohmic redox waves overlapped simultaneously with photocurrents due to the Schottky junction. Additionally, a second step photocurrent generation was observed in the presence of both MeOH and

• potential; nanoporous TiO2 thin film; photocurrent; Schottky junction and ohmic contact; Introduction Photoelectrocatalytic reactions at semiconductor electrodes were investigated before the 1960s [1][2]. A semiconductor electrode forms a type of Schottky junction with liquid electrolytes called a liquid