**3.1 Colloidal synthesis of lead-sulfosalt nanocrystals with different shapes and sizes**

Controlling the structural and optoelectronic properties of PbS nanostructures through improved hot-colloidal chemistry remains a very active field of research. As shown in Figure 6, the recent evolution of the early hot-colloidal lead-salt nanocrystal synthesis (Hines & Scholes, 2003) has lead to more complex nanostructures including nanorods & nanowires (Acharya et al., 2008; Dom et al., 2009; Ge et al., 2005; Yong et al., 2006; F. Zhang & Wong, 2009), star-shaped nanocrystals (Lee et al., 2002; Zhu et al., 2007), nanocubes (Zhao & Qi, 2006), octahedral nanocrystals (Cho et al., 2005; Koh et al., 2010) and core-shell nanocrystals (Petryga et al., 2008; Stouwdam et al., 2007; Swart et al., 2010; Warner & Cao, 2008). Most of these developments have occurred over the last five years.

Fig. 6. Colloidal synthesis of exotic PbS nanostructures. (a) Typical PbS quantum dot, (b) PbS/CdS core-shell nanocrystal, (c) PbS nanocubes, (d) star-shaped PbS nanocrystals and (e) PbS nanowires, all synthesized in our lab using variations of the hot-colloidal method. The inset in (e) shows the selective area electron diffraction (SAED) used to confirm the singlecrystal structure of the nanowires.

As shown in Figure 5, the TFB:F8BT conjugated polymer-based heterostructures also constitute an ideal host system for PbS semiconductor nanocrystals to provide low-cost and high-performance hybrid heterostructures for key applications such as lighting & displays, biomedical devices, lab-on-a-chip, flexible optoelectronics, night-vision and solar-energy

Fig. 5. Hybrid polyfluorene-based light-emitting heterostructures. (a) The TFB:F8BT system provides an ideal host system for PbS nanocrystal incorporation. (b) The incorporation of PbS nanocrystals can migrate their operation to the near-infrared (between 900 - 1600 nm),

**3.1 Colloidal synthesis of lead-sulfosalt nanocrystals with different shapes and sizes**  Controlling the structural and optoelectronic properties of PbS nanostructures through improved hot-colloidal chemistry remains a very active field of research. As shown in Figure 6, the recent evolution of the early hot-colloidal lead-salt nanocrystal synthesis (Hines & Scholes, 2003) has lead to more complex nanostructures including nanorods & nanowires (Acharya et al., 2008; Dom et al., 2009; Ge et al., 2005; Yong et al., 2006; F. Zhang & Wong, 2009), star-shaped nanocrystals (Lee et al., 2002; Zhu et al., 2007), nanocubes (Zhao & Qi, 2006), octahedral nanocrystals (Cho et al., 2005; Koh et al., 2010) and core-shell nanocrystals (Petryga et al., 2008; Stouwdam et al., 2007; Swart et al., 2010; Warner & Cao,

Fig. 6. Colloidal synthesis of exotic PbS nanostructures. (a) Typical PbS quantum dot, (b) PbS/CdS core-shell nanocrystal, (c) PbS nanocubes, (d) star-shaped PbS nanocrystals and (e) PbS nanowires, all synthesized in our lab using variations of the hot-colloidal method. The inset in (e) shows the selective area electron diffraction (SAED) used to confirm the single-

2008). Most of these developments have occurred over the last five years.

harvesting device architectures.

depending on the their size.

crystal structure of the nanowires.
