(a) Optical absorption spectra of close-packed and sparse-packed AuNP film S1 and S2, respectively. For comparison, the spectrum of a Au reference film consisting of very densely packed Au particles is also shown. The spectra are normalized to the interband peak at 380 nm. (b) TEM image of the AuNPs with an average diameter of 3.3 nm used in this work. (c) and (d) are the AFM height and phase images of the Au reference film, respectively.
Evolution of simulated optical absorption of AuNP ensembles with different packing density . The inset shows the simple cubic packing of AuNPs assumed in the simulation: a constant NP radius of is kept, while the inter-NP spacing is varied to mimic different NP packing density . The intensity of the spectra has been adjusted for easy comparison of the peak position and shape.
(a): (i) irradiance spectrum (at 0.5 m) of the 300 W Xe lamp used in the experiments. The spectrum is reproduced from Ref. 29; (ii) photon flux of the Xe lamp determined using a calibrated commercial Si photodetector; and (iii) photocurrent and dark current recorded for AuNPs. (b): (i) Optical absorption spectrum of the close-packed AuNP network; (ii) and (iii) are the quantum yield spectra of AuNPs obtained under 5 and 0 V bias voltage, respectively.
(a) Proposed inter-AuNP photoejection and photoelectron delocalization model. (b) Bias-dependence of observed for and 1064 nm, respectively. The empty circles are the experimental data, while the solid lines are fits to the power-law.
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