Figure 2. PbSe NR photovoltaic devices.

(a) Cross-sectional TEM outlining the device architecture (see Supplementary Fig. 6 for details on compositional analysis) and (b) energy alignment as determined by a combination of ultraviolet photoelectron spectroscopy (UPS) and absorbance spectroscopy. (c) I–V characteristics of depleted heterojunction solar cells consisting of PbSe NRs with bandgaps 0.80 eV (green), 0.95 eV (blue) and 1.05 eV (red). The dark currents are shown as dashed lines and the I–V curves under illumination are shown as solid lines. We show the averaged performance of multiple independent solar cells (six cells for 1.05 eV, five cells for 0.95 eV and five cells for 0.80 eV) in dark lines and the spread as a shaded area around the mean.