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Study of Radial Tunnel Diodes based on Heterostructure Nanowires

Tizno, Ofogh LU (2013) FYSM60 20131
Department of Physics
Abstract
In this project, Esaki tunnel diodes have been made of InP(n+)/InGaAs(p+) core/sell nanowires and current-voltage characteristics of the nanowire tunnel diodes for future electronic and photovoltaic application have been investigated.
Six different groups of nanowires with different doping concentrations of the shell have been studied with the aim of finding the best nanowire condition to use in the processing of the periodical array of nanowire solar cells. All processing steps have been defined and optimized individually and electrical measurements have been performed at a range of different temperatures from room temperature to 4.2K.
Nanowires grown with different DEZn molar fraction from 3.3×10-6 to 9.4×10-5 have been investigated.... (More)
In this project, Esaki tunnel diodes have been made of InP(n+)/InGaAs(p+) core/sell nanowires and current-voltage characteristics of the nanowire tunnel diodes for future electronic and photovoltaic application have been investigated.
Six different groups of nanowires with different doping concentrations of the shell have been studied with the aim of finding the best nanowire condition to use in the processing of the periodical array of nanowire solar cells. All processing steps have been defined and optimized individually and electrical measurements have been performed at a range of different temperatures from room temperature to 4.2K.
Nanowires grown with different DEZn molar fraction from 3.3×10-6 to 9.4×10-5 have been investigated. The resulted I-V characteristics of different devices show a clear tunneling behavior at room temperature with an obvious decrease of the amount of excess current at lower temperatures. Devices made with the lowest DEZn molar fraction during growth of the InGaAs shell, showed a borderline diode behavior, almost the same as a traditional p-n junction at forward biases with an increased reverse current due to partly tunneling effect at negative biases. By increasing the Zn precursor flow, devices exhibited higher tunneling currents and PVCRs. At room temperature a maximum of 23.32 nA and 6.1 µA (at V=-0.5V) have been measured for the peak and reverse currents respectively. The highest PVCR obtained at room temperature was 13.6 which increased dramatically to 103.4 at liquid helium temperature.
For the highest DEZn molar fraction, nanowires may reach a saturation point of Zn concentration which severely affects their electrical properties and the devices made from these nanowires showed individual electrical characteristics. Since the devices fabricated in the vertical processing were made of the nanowires from this group of doping concentration, it made some difficulties to gain tunneling currents from these samples. (Less)
Please use this url to cite or link to this publication:
author
Tizno, Ofogh LU
supervisor
organization
course
FYSM60 20131
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Tunnel diode, Esaki diode, Heterostructure, Nanowire, Core/shell, InP, InGaAs, Electrical characterization, Doping, Solar cell
language
English
id
4178483
date added to LUP
2013-12-01 12:09:30
date last changed
2013-12-01 12:09:30
@misc{4178483,
  abstract     = {In this project, Esaki tunnel diodes have been made of InP(n+)/InGaAs(p+) core/sell nanowires and current-voltage characteristics of the nanowire tunnel diodes for future electronic and photovoltaic application have been investigated.
Six different groups of nanowires with different doping concentrations of the shell have been studied with the aim of finding the best nanowire condition to use in the processing of the periodical array of nanowire solar cells. All processing steps have been defined and optimized individually and electrical measurements have been performed at a range of different temperatures from room temperature to 4.2K.
Nanowires grown with different DEZn molar fraction from 3.3×10-6 to 9.4×10-5 have been investigated. The resulted I-V characteristics of different devices show a clear tunneling behavior at room temperature with an obvious decrease of the amount of excess current at lower temperatures. Devices made with the lowest DEZn molar fraction during growth of the InGaAs shell, showed a borderline diode behavior, almost the same as a traditional p-n junction at forward biases with an increased reverse current due to partly tunneling effect at negative biases. By increasing the Zn precursor flow, devices exhibited higher tunneling currents and PVCRs. At room temperature a maximum of 23.32 nA and 6.1 µA (at V=-0.5V) have been measured for the peak and reverse currents respectively. The highest PVCR obtained at room temperature was 13.6 which increased dramatically to 103.4 at liquid helium temperature. 
 For the highest DEZn molar fraction, nanowires may reach a saturation point of Zn concentration which severely affects their electrical properties and the devices made from these nanowires showed individual electrical characteristics. Since the devices fabricated in the vertical processing were made of the nanowires from this group of doping concentration, it made some difficulties to gain tunneling currents from these samples.},
  author       = {Tizno, Ofogh},
  keyword      = {Tunnel diode,Esaki diode,Heterostructure,Nanowire,Core/shell,InP,InGaAs,Electrical characterization,Doping,Solar cell},
  language     = {eng},
  note         = {Student Paper},
  title        = {Study of Radial Tunnel Diodes based on Heterostructure Nanowires},
  year         = {2013},
}