enhanced up to 25 and 50 times that of the pristine NW, respectively. Below the
ED C , the positions and intensities of the LCM PL peaks were red-shifted and
increased with the E-beam dose. However, the emission intensity of the sections
treated with a dose higher than the ED C was considerably lower (inset of Fig. 23e).
Therefore, the PL color and intensity of single P3MT NWs can be tailored precisely
at the nanoscale level as a function of the focused E-beam dose.
Figure 23f shows the micro-Raman spectra of pristine and treated P3MT NW
sections and reveals the structural and doping characteristics. Significant
differences in the micro-Raman spectra associated with the focused E-beam treatment were observed in the range of 1,050À1,650 cm
À1
. The intensities of the
Raman peaks at 1,192, 1,223, and 1,361 cm
À1 , corresponding to C β –H bending,
antisymmetric C α –C α ring stretching, and C β –C β ring stretching deformation
modes, respectively [67, 68, 134], decreased with increasing E-beam dose [67].
Fig. 23 (a) Focused E-beam treatment at designated positions of a single NW. (b) Color CCD
images of single P3MT NWs treated with focused E-beam doses of 7.5 Â 10
16 electrons/cm
2 (left),
2.5 Â 10
17 electrons/cm
2 (middle), and 2.5 Â 10
18 electrons/cm
2 (right). Insets: Images of focused
E-beam-treated P3MT NWs with different section lengths. The arrows indicate the treated sections.
(c) 3D LCM PL images of corresponding samples in (b) and their insets. The color scale bar on the
right represents the photon counts. (d) Averaged LCM PL intensity of P3MT NW sections treated
with a focused E-beam as a function of dose. (e) LCM PL spectra of the pristine P3MT NW sections
and of sections treated with various focused E-beam doses. Inset: magnified LCM PL spectra of
pristine sections and of the sections treated with a high dose of 2.5 Â 10
18 electrons/cm
2
.
(f) Normalized micro-Raman spectra for pristine and treated P3MT NW sections at various doses.
(Reproduced with permission from [62]. Copyright 2011 Wiley-VCH.)
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Y.K. Hong et al.
ED C , the positions and intensities of the LCM PL peaks were red-shifted and
increased with the E-beam dose. However, the emission intensity of the sections
treated with a dose higher than the ED C was considerably lower (inset of Fig. 23e).
Therefore, the PL color and intensity of single P3MT NWs can be tailored precisely
at the nanoscale level as a function of the focused E-beam dose.
Figure 23f shows the micro-Raman spectra of pristine and treated P3MT NW
sections and reveals the structural and doping characteristics. Significant
differences in the micro-Raman spectra associated with the focused E-beam treatment were observed in the range of 1,050À1,650 cm
À1
. The intensities of the
Raman peaks at 1,192, 1,223, and 1,361 cm
À1 , corresponding to C β –H bending,
antisymmetric C α –C α ring stretching, and C β –C β ring stretching deformation
modes, respectively [67, 68, 134], decreased with increasing E-beam dose [67].
Fig. 23 (a) Focused E-beam treatment at designated positions of a single NW. (b) Color CCD
images of single P3MT NWs treated with focused E-beam doses of 7.5 Â 10
16 electrons/cm
2 (left),
2.5 Â 10
17 electrons/cm
2 (middle), and 2.5 Â 10
18 electrons/cm
2 (right). Insets: Images of focused
E-beam-treated P3MT NWs with different section lengths. The arrows indicate the treated sections.
(c) 3D LCM PL images of corresponding samples in (b) and their insets. The color scale bar on the
right represents the photon counts. (d) Averaged LCM PL intensity of P3MT NW sections treated
with a focused E-beam as a function of dose. (e) LCM PL spectra of the pristine P3MT NW sections
and of sections treated with various focused E-beam doses. Inset: magnified LCM PL spectra of
pristine sections and of the sections treated with a high dose of 2.5 Â 10
18 electrons/cm
2
.
(f) Normalized micro-Raman spectra for pristine and treated P3MT NW sections at various doses.
(Reproduced with permission from [62]. Copyright 2011 Wiley-VCH.)
232
Y.K. Hong et al.