| AVS 61st International Symposium & Exhibition | |
| Electronic Materials and Processing | Monday Sessions |
| Session EM-MoA |
| Session: | Nanoparticles for Electronic Materials |
| Presenter: | Diogenes Placencia, Naval Research Laboratory |
| Authors: | D. Placencia, Naval Research Laboratory J.E. Boercker, Naval Research Laboratory E.E. Foos, Naval Research Laboratory J.G. Tischler, Naval Research Laboratory |
| Correspondent: | Click to Email |
PbSe nanorods are attractive for use in next-generation optoelectronic devices due to their exceptional physical properties such as larger Stokes shifts and more efficient multiple exciton generation (MEG), relative to spherical nanocrystals.1-3 However, further development of PbSe nanorods for viable technological components requires precise control of the nanorod diameter and length as well as an understanding of how the nanorod dimensions affect their optoelectronic properties. We have investigated the nature of the PbSe nanorod synthesis, yielding an understanding of how to independently control the nanorod diameter and length. Additionally we have developed an elementary comprehension of how the nanorod dimensions affect their optical properties.
Recently, single-crystal, homogeneous, PbSe nanorods were synthesized using a solution synthesis.4 In our work, we show that water present in this synthesis has a dramatic effect on the nanorod aspect ratio and yield. By varying the water concentration from 0 to 204 mM, the nanorod aspect ratio and yield can be controlled from 1.1 to 10 and 1 to 14%, respectively. Water indirectly affects the nanorod morphology and yield by reacting with the tris(diethylamino)phosphine used in the reaction to form bis(diethylamido)phosphorus acid. The latter is responsible for both the nanorod aspect ratio and yield variations. Furthermore, the excess oleic acid in the reaction can also create bis(diethylamido)phosphorus acid from tris(diethylamino)phosphine. When both excess oleic acid and water are removed, the reaction slows and highly uniform, non-branching, nanorods are formed.5
Exploration of various synthetic parameters (e.g., temperature, reaction time) within the nanorod reaction free of water and excess oleic acid resulted in our ability to independently control the nanorod diameter and length. Aspect ratios ranging from 1 to 14 have been synthesized, showing no branching, varying levels of quantum yields, and a wide absorption energy range (~1200 nm – 2000 nm).
References
[1] Tischler J G, Kennedy T A, Glaser E R, Efros A L, Foos E E, Boercker J E, Zega T J, Stroud R M and Erwin S C 2010 Phys. Rev. B 82 245303
[2] Cunningham P D, Boercker J E, Foos E E, Lumb M P, Smith A R, Tischler J G and Melinger J S 2011 Nano Lett. 11 3476
[3] Sandberg R L, Padilha L A, Qazilbash M M, Bae W K, Schaller R D, Pietryga J M, Stevens M J, Baek B, Nam S W and Klimov V I 2012 ACS Nano 6 9532
[4] Koh W-K, Bartnik A C, Wise F W and Murray C B 2010 JACS 132 3909
[5] Boercker J E, Foos E E, Placencia D and Tischler J G 2013 JACS 135 15071