Scanning Probe Microscopy Conductivity Measurements of InP Nanowires for Solar cells
(2013) FYSM31 20131Synchrotron Radiation Research
Department of Physics
- Abstract
- This thesis is devoted to the analysis of the I-V properties of axial InP pn-junction nanowires made for solar cell application. A novel method has been used to measure the I-V characteristics very accurately and reproducibly, using scanning tunneling microscopy (STM). The STM is used to first image the nanowires from top and then form a low resistive point contact between the STM tip and an individual nanowire, which is still on its growth substrate, in ultrahigh vacuum conditions. This setup is well suited to investigate the I-V characteristics of individual nanowires with high accuracy and statistical relevance.
In particular, the I-V curves are first analyzed to evaluate when a low resistive point contact has been established. Then,... (More) - This thesis is devoted to the analysis of the I-V properties of axial InP pn-junction nanowires made for solar cell application. A novel method has been used to measure the I-V characteristics very accurately and reproducibly, using scanning tunneling microscopy (STM). The STM is used to first image the nanowires from top and then form a low resistive point contact between the STM tip and an individual nanowire, which is still on its growth substrate, in ultrahigh vacuum conditions. This setup is well suited to investigate the I-V characteristics of individual nanowires with high accuracy and statistical relevance.
In particular, the I-V curves are first analyzed to evaluate when a low resistive point contact has been established. Then, I-V characteristics of nanowires before and after sample cleaning are obtained in order to compare the effect of the surface oxide layer on the nanowire electric properties. The InP pn-junction nanowires show rectifying behavior with typical ideality factors between 2.5 and 2.6. When the surface oxide is removed from the nanowires by annealing under atomic hydrogen background, the ideality factor slightly improves and the conductivity of the individual nanowires increases dramatically for both reverse and forward bias. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/3559203
- author
- Irfan, Mubashar LU
- supervisor
-
- Rainer Timm LU
- organization
- course
- FYSM31 20131
- year
- 2013
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Nanowire, Semicondutor, Solar energy, Photovoltaic
- language
- English
- id
- 3559203
- date added to LUP
- 2013-03-07 19:53:22
- date last changed
- 2013-03-07 19:53:22
@misc{3559203, abstract = {{This thesis is devoted to the analysis of the I-V properties of axial InP pn-junction nanowires made for solar cell application. A novel method has been used to measure the I-V characteristics very accurately and reproducibly, using scanning tunneling microscopy (STM). The STM is used to first image the nanowires from top and then form a low resistive point contact between the STM tip and an individual nanowire, which is still on its growth substrate, in ultrahigh vacuum conditions. This setup is well suited to investigate the I-V characteristics of individual nanowires with high accuracy and statistical relevance. In particular, the I-V curves are first analyzed to evaluate when a low resistive point contact has been established. Then, I-V characteristics of nanowires before and after sample cleaning are obtained in order to compare the effect of the surface oxide layer on the nanowire electric properties. The InP pn-junction nanowires show rectifying behavior with typical ideality factors between 2.5 and 2.6. When the surface oxide is removed from the nanowires by annealing under atomic hydrogen background, the ideality factor slightly improves and the conductivity of the individual nanowires increases dramatically for both reverse and forward bias.}}, author = {{Irfan, Mubashar}}, language = {{eng}}, note = {{Student Paper}}, title = {{Scanning Probe Microscopy Conductivity Measurements of InP Nanowires for Solar cells}}, year = {{2013}}, }