Related Experiment Video
Updated: Feb 23, 2026
11:33
All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
10.3K
Probing Intrawire, Interwire, and Diameter-Dependent Variations in Silicon Nanowire Surface Trap Density with
Emma E M Cating1, Christopher W Pinion1, Joseph D Christesen1
1Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
Nano Letters
|September 13, 2017
Summary
Surface trap density in silicon nanowires (NWs) impacts device performance. This study reveals significant variations in surface quality between NWs, highlighting the need for careful fabrication to manage these effects.
Area of Science:
- Materials Science
- Nanotechnology
- Semiconductor Physics
Background:
- Surface trap density critically influences silicon nanowire (NW) device performance.
- Understanding surface recombination dynamics is essential for optimizing NW-based electronics.
Purpose of the Study:
- To quantitatively characterize surface recombination velocity (S) and its spatial variation in silicon NWs.
- To investigate the relationship between NW diameter, surface quality, and recombination lifetime (τ).
Main Methods:
- Pump-probe microscopy was employed to measure recombination lifetime (τ) at distinct locations within individual silicon NWs.
- Surface recombination velocity (S) was calculated using the formula S = d/4τ, where d is the NW diameter.
- The study analyzed 301 silicon NWs grown via the vapor-liquid-solid (VLS) method.
Main Results:
- Surface recombination velocity (S) exhibited significant inter-NW variability (up to 2 orders of magnitude) but limited intra-NW variation (factor of 2-3).
- Smaller diameter NWs showed shorter recombination lifetimes (τ) due to both geometric effects and poorer surface quality (higher S).
Conclusions:
- Inter-NW heterogeneity in surface quality is a major factor affecting silicon NW performance.
- Diameter-dependent surface effects must be considered alongside geometric influences in NW device design and fabrication.
- Optimizing NW growth processes is crucial to minimize surface trap density and improve device consistency.
