| AVS 55th International Symposium & Exhibition | |
| Energy Science and Technology Focus Topic | Tuesday Sessions |
| Session EN-TuP |
| Session: | Energy Focus Topic Poster Session |
| Presenter: | D.D.T. Mastrogiovanni, Rutgers University |
| Authors: | L.A. Klein, Rutgers University D.D.T. Mastrogiovanni, Rutgers University A. Du Pasquier, Rutgers University E. Garfunkel, Rutgers University |
| Correspondent: | Click to Email |
Single crystal germanium nanowires are grown via vapor-liquid-solid methods in a hot-wall chemical vapor deposition reactor. We present the results of nanowire growth and discuss potential applications of nanowires grown on a variety of substrates. The relatively low growth temperature required for germanium nanowire formation combined with the enhanced semiconducting properties such as higher carrier mobility of germanium over silicon makes these wires an attractive building block in the rapidly expanding field of nanotechnology. In addition to our investigations into how growth conditions and substrates can affect the shape and orientation of the nanowires, we have investigated various chemical passivation methods, including chlorination, H-termination, and thiol and alkene passivation. Passivation becomes of utmost importance for germanium devices as germanium does not possess a stable native oxide as does silicon. These chemistries are also used to facilitate further surface functionalization and ohmic formation, and to improve device electrical performance. Most recently, the germanium nanowires were also used to enhance the properties of organic photovoltaic devices through the creation of a bulk heterojunction solar cell with poly(3-hexylthiophene) (P3HT). This hybrid-inorganic/organic device exhibits a significant increase in exciton dissociation and photocurrent when compared to pure P3HT. The photoelectrical properties of this device are characterized by measuring absorbance and photoluminescence spectra, current-voltage curves, and AM 1.5 filtered external quantum efficiency. In addition to the aforementioned techniques, other studies utilizing x-ray diffraction, Rutherford backscattering spectroscopy, and inductively coupled plasma mass spectroscopy enable us to observe how variations in nanowire concentration can affect the relative crystallinity and crystallite orientation of P3HT. We conclude with a discussion of our plans to improve the performance of these devices through surface passivation and the controlled introduction of phosphine impurities.