| About this Abstract |
| Meeting |
2011 Electronic Materials Conference
|
| Symposium
|
2011 Electronic Materials Conference
|
| Presentation Title |
KK7, Electrochemically Deposited Branched Indium Antimonide (InSb) Nanowire Arrays as “In-Situ” Anti-Reflective Structures |
| Author(s) |
Asaduzzaman Mohammad, Suprem R. Das, Mohammad Ryyan Khan, Muhammad Ashraful Alam, David B. Janes |
| On-Site Speaker (Planned) |
Asaduzzaman Mohammad |
| Abstract Scope |
Semiconductor nanowire arrays, as opposed to their bulk counterparts, exhibit properties that may be of interest for next-generation photovoltaics and optoelectronic applications. For detectors and photovoltaic applications, vertical arrays of nanowires offer the potential to de-couple the two relevant length scales, i.e. the optical absorption length and the distance a photo-generated carrier must travel to be collected. Nanowire arrays also offer the possibility to change the overall electromagnetic environment, basically through tapering that causes the transition between air and the absorbing semiconductor region [1]. Bulk Indium Antimonide (InSb) is an interesting material for infrared detectors due to its low and direct bandgap (E<SUB>g</SUB> = 0.17eV at 300K). However, a semi-infinite InSb slab would have ~ 40% optical reflectance due to the significant impedance mismatch with air; thereby almost half of the incident light does not contribute to any device performance. In this work, we developed branched InSb nanowire arrays by electrochemical deposition into the partially branched pores of a porous anodic alumina (PAA) template. The branched nanowires exhibited a diameter of around 20 nm on the top branches and widened to a diameter of about 100 to 150 nm at the stems of the wires. Following etching of the alumina matrix to expose several microns of the branched wires (~ 20μm from the top surface), the structure exhibited a very low reflectance (less than 5%) in the near infrared range (0.75 μm ≤ λ ≤ 2 μm). The branched structures provide a unique tapered transition between air and the body of the InSb nanowires. A detailed theoretical model considering the various length dimensions of the tapered region was developed to interpret our observed experimental data and explore the potential of such structure for optoelectronic applications. |
| Proceedings Inclusion? |
Undecided |