Supporting Information - Royal Society of Chemistry

Electronic Supplementary Material (ESI) for Energy & Environmental Science
This journal is © The Royal Society of Chemistry 2013
Table S1. Atomic concentration of graphite, GO, RGO, and N-RGO
C
(atomic %)
O
(atomic %)
N
(atomic %)
C/O
ratio
Graphite 99.44 0.56
GO 63.18 32.65 1.55 1.94
RGO 88.78 11.22 - 7.91
N-RGO 86.52 5.19 7.44 16.67
Table S2. Proportion of N-P and N-Q with various thermal reduction temperatures
N-P (%) N-Q (%)
Ratio
(Nq/Np)
300 o C 75 25 0.33
500 o C 33 66 1.98
700 o C 49 51 1.01
Table S3. Photovoltaic parameters of OPV cells of RGO/P3HT:PCBM and N-RGO/P3HT:PCBM in this work
J SC [mA/cm 2 ] V OC [V] FF PCE [%]
Pristine
P3HT:PCBM
10.54 ± 0.11 0.58 ± 0.01 0.51 ± 0.01 3.12 ± 0.07
RGO 0.1wt% 12.69 ± 0.31 0.53 ± 0.01 0.40 ± 0.01 2.71 ± 0.17
RGO 0.5wt% 7.37 ± 0.29 0.54 ± 0.01 0.40 ± 0.01 1.61 ± 0.09
RGO 1wt% 6.57 ± 0.10 0.45 ± 0.01 0.38 ± 0.01 1.06 ± 0.03
N-RGO 0.1wt% 12.96 ± 0.41 0.56 ± 0.01 0.50 ± 0.01 3.65 ± 0.19
N-RGO 0.5wt% 14.86 ± 0.09 0.58 ± 0.01 0.50 ± 0.01 4.39 ± 0.09
N-RGO 1wt% 14.86 ± 0.58 0.58 ± 0.02 0.46 ± 0.03 4.06 ± 0.29
Table S4. Charge carrier motilities: PCBM-only devices (electron) and P3HT-only devices (hole). The concentration of graphene is 1 wt%
Electron mobility
(PCBM only devices)
(m 2 V −1 s –1 )
Hole mobility
(P3HT only devices)
(m 2 V −1 s –1 )
without graphene 3.1×10 -7 7.3×10 -8
RGO 3.2×10 -7 5.6×10 -8
N-RGO (1 wt%) 5.4×10 -7 4.4×10 -8