| AVS 58th Annual International Symposium and Exhibition | |
| Energy Frontiers Focus Topic | Wednesday Sessions |
| Session EN+EM+NS-WeM |
| Session: | Quantum Dot and Nanowire Solar Cells |
| Presenter: | Michael Filler, Georgia Institute of Technology |
| Authors: | N. Shin, Georgia Institute of Technology I.R. Musin, Georgia Institute of Technology S. Sivaram, Georgia Institute of Technology M.A. Filler, Georgia Institute of Technology |
| Correspondent: | Click to Email |
Semiconductor nanowires offer exciting opportunities to engineer light absorption and carrier transport for ultrahigh efficiency photovoltaic devices. The precise control of crystal structure and geometry is required to achieve a desired behavior, especially in highly confined nanoscale systems. In the ideal situation, the combination of nanowire diameter, lattice structure (e.g. diamond cubic, wurtzite), crystal orientation (e.g. <111> vs. <110>), and sidewall faceting that yields the most robust device performance would be known and could be rationally synthesized. Unfortunately, an inadequate understanding of nanowire chemistry-structure and structure-property relationships prevents the accomplishment of this task with bottom-up syntheses at the present time. This presentation will provide an overview of our recent efforts to bridge this knowledge gap. In our research, in-situ infrared spectroscopy is combined with an ultrahigh vacuum growth environment to fundamentally correlate nanowire chemistry with photophysics, while circumventing the sample degradation that can obscure the intrinsic properties of nanoscale structures. Group IV nanowires and their heterostructures are a model system and are fabricated with the vapor-liquid-solid (VLS) growth technique. The critical influence of surface-bound species near the three-phase boundary and their impact on nanowire crystal structure will be discussed in detail. This fundamental knowledge opens a generic and highly tunable route to engineer multiple classes (e.g. group IV and III-V, etc.) of semiconductor nanowires, heterostructures, and superstructures for advanced photovoltaic device applications.