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Development of Single Nanowire Optoelectronic Devices

Lamers, Nils LU (2025)
Abstract
Semiconductor nanowires (NW) have been of interest to optoelectronics research for several decades due to the unique optical effects resulting from their geometry. Today, NWs are fabricated from a wide range of materials, ranging from Si to III-Vs and emerging materials like metal-halide perovskites (MHPs). Among NW devices, single NW devices are of special interest because they offer both a useful low-dimensional test platform for transport and optical phenomena and because they have potential for ultra-high-resolution applications, which could surpass currently established display and photodetector array technologies. At the same time, single NW devices represent a unique challenge to semiconductor processing, requiring a high degree of... (More)
Semiconductor nanowires (NW) have been of interest to optoelectronics research for several decades due to the unique optical effects resulting from their geometry. Today, NWs are fabricated from a wide range of materials, ranging from Si to III-Vs and emerging materials like metal-halide perovskites (MHPs). Among NW devices, single NW devices are of special interest because they offer both a useful low-dimensional test platform for transport and optical phenomena and because they have potential for ultra-high-resolution applications, which could surpass currently established display and photodetector array technologies. At the same time, single NW devices represent a unique challenge to semiconductor processing, requiring a high degree of precision and control.
This thesis addresses the manufacturing challenges of two optoelectronic materials systems by developing novel processes for manufacturing single NW devices. For the III-V InP, an established semiconductor, this challenge consists in pushing from larger area vertical NW devices towards single vertical NW devices which ultimately unlock ultra-high-resolution photodetector and display applications. For the MHP CsPbBr3, the challenge consists of pushing towards nanostructured devices that can combine the advantages of MHPs with nanoscale engineering. This in turn requires a re-development and re-thinking of established processes in an MHP-compatible manner.
Papers I and II address vertical single NW InP devices, a device geometry which has been rarely reported but is ultimately necessary for photodetector and display applications based on single InP NWs. The devices are based on single vertical NWs of 60 nm diameter, contacted inside a NW array (paper I). We demonstrate a high yield fabrication process for quality single NW devices with ideality factors as low as n = 1.8. These NWs work as LEDs, solar cells, and photodetectors. We take advantage of the low NW diameter to use the single NW photodetectors for ultra-high-resolution imaging of an optical focus at a 70 nm step size. The resulting images allow us to characterise the beam parameters but also reveal additional details in the intensity distribution which may be invisible with other methods (paper II).
Papers III to VI address the nanofabrication of MHPs, specifically horizontal CsPbBr3 NWs. Papers III and VI deal with CsPbBr3 NW solvent-based synthesis using anodised aluminium oxide templates, a low-cost method when compared to the established metal-organic vapour phase methods used for III-V materials. Paper IV develops an MHP-compatible electron-beam lithography processes which allows us to create nanostructured contacts of our CsPbBr3 NWs. In paper V, we demonstrate a gas-phase anion exchange process to create CsPb(Br1-xClx)3 NWs from CsPbBr3 NWs. We demonstrate how the combination of the EBL and anion exchange processes can be used to create heterostructured NWs which could form the building blocks of future nanostructured MHP optoelectronic devices.
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Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Roeffaers, Maarten, KU Leuven, Belgien
organization
publishing date
type
Thesis
publication status
published
subject
keywords
nanowire, metal-halide perovskites, III-V semiconductor, photodetector, EBL
pages
206 pages
publisher
Lund University
defense location
Rydbergsalen
defense date
2025-03-21 09:00:00
ISBN
978-91-8104-407-2
978-91-8104-406-5
language
English
LU publication?
yes
id
9809b767-d495-44ed-b431-77c8198665c6
date added to LUP
2025-02-20 13:59:10
date last changed
2025-04-04 14:03:26
@phdthesis{9809b767-d495-44ed-b431-77c8198665c6,
  abstract     = {{Semiconductor nanowires (NW) have been of interest to optoelectronics research for several decades due to the unique optical effects resulting from their geometry. Today, NWs are fabricated from a wide range of materials, ranging from Si to III-Vs and emerging materials like metal-halide perovskites (MHPs). Among NW devices, single NW devices are of special interest because they offer both a useful low-dimensional test platform for transport and optical phenomena and because they have potential for ultra-high-resolution applications, which could surpass currently established display and photodetector array technologies. At the same time, single NW devices represent a unique challenge to semiconductor processing, requiring a high degree of precision and control.<br/>This thesis addresses the manufacturing challenges of two optoelectronic materials systems by developing novel processes for manufacturing single NW devices. For the III-V InP, an established semiconductor, this challenge consists in pushing from larger area vertical NW devices towards single vertical NW devices which ultimately unlock ultra-high-resolution photodetector and display applications. For the MHP CsPbBr3, the challenge consists of pushing towards nanostructured devices that can combine the advantages of MHPs with nanoscale engineering. This in turn requires a re-development and re-thinking of established processes in an MHP-compatible manner.<br/>Papers I and II address vertical single NW InP devices, a device geometry which has been rarely reported but is ultimately necessary for photodetector and display applications based on single InP NWs. The devices are based on single vertical NWs of 60 nm diameter, contacted inside a NW array (paper I). We demonstrate a high yield fabrication process for quality single NW devices with ideality factors as low as n = 1.8. These NWs work as LEDs, solar cells, and photodetectors. We take advantage of the low NW diameter to use the single NW photodetectors for ultra-high-resolution imaging of an optical focus at a 70 nm step size. The resulting images allow us to characterise the beam parameters but also reveal additional details in the intensity distribution which may be invisible with other methods (paper II).<br/>Papers III to VI address the nanofabrication of MHPs, specifically horizontal CsPbBr3 NWs. Papers III and VI deal with CsPbBr3 NW solvent-based synthesis using anodised aluminium oxide templates, a low-cost method when compared to the established metal-organic vapour phase methods used for III-V materials. Paper IV develops an MHP-compatible electron-beam lithography processes which allows us to create nanostructured contacts of our CsPbBr3 NWs. In paper V, we demonstrate a gas-phase anion exchange process to create CsPb(Br1-xClx)3 NWs from CsPbBr3 NWs. We demonstrate how the combination of the EBL and anion exchange processes can be used to create heterostructured NWs which could form the building blocks of future nanostructured MHP optoelectronic devices.<br/>}},
  author       = {{Lamers, Nils}},
  isbn         = {{978-91-8104-407-2}},
  keywords     = {{nanowire; metal-halide perovskites; III-V semiconductor; photodetector; EBL}},
  language     = {{eng}},
  publisher    = {{Lund University}},
  school       = {{Lund University}},
  title        = {{Development of Single Nanowire Optoelectronic Devices}},
  url          = {{https://lup.lub.lu.se/search/files/208804494/Nils_Lamers_-_WEBB.pdf}},
  year         = {{2025}},
}