top of page

PRIN Project

​​

Nanowires (NWs) are quasi-1D crystals with nanoscale diameters and several microns in length. 

This project aims at growing and thoroughly investigating quantum dots (QDs) and superlattices (SLs) in two different III-V NW heterostructures: GaAsP/GaP NWs, for photonic and optoelectronic applications in the visible-near infrared range, and InAsP/InP NWs, for telecom-wavelengths applications.

 

The well-known vapor-liquid-solid growth approach will be employed to realize bottom-up NWs incorporating QDs of controllable size, position and chemical composition. In particular, we will use the chemical beam epitaxy technique, which combines the advantages of ultra-high-vacuum epitaxial growth with the ease of use and flexibility given by metalorganic precursor gas sources. The controlled NW morphology and diameter will be exploited for the optimization of the waveguiding properties of NWs for the nested QDs.

​
​​

Scanning electron microscopy (SEM) for morphology characterization and energy dispersive x-ray spectroscopy (EDX) for compositional analysis are performed in-house with a field emission gun (FEG) electron microscope operating up to 30 kV. Electron Beam Lithography (EBL) for substrate patterning is performed instead with a dedicated FEG SEM equipped with an interferometric stage.

 

​

MBE.bmp

The CNR unit in Pisa has a remarkable expertise in the growth and structural characterization of III-V semiconductor nanowires, axial and radial nanowire heterostructures, and selective area nanostructures. The Chemical Beam Epitaxy (CBE) system and the cleanroom facility of the National Enterprise for nanoScience and nanoTechnology (NEST) Laboratory of Scuola Normale Superiore, where the Nanoscience institute of CNR is headquartered are fully available for the project.The CBE is equipped with a Riber Compact-21 growth chamber with an integrated Reflection of High Energy Electron Diffraction (RHEED) system for in-situ monitoring and an optical pyrometer for the substrate temperature measurement. Available group-V materials are arsenic (TBAs), phosphorous (TBP), and antimony (TDMASb and TMSb); for group III there are indium (TMIn), gallium (TEGa), and aluminium (TMAl) precursors.​

Transmission electron microscopy (TEM) to investigate the nanowires structural quality (crystal phase, interface sharpness, strain distribution) is also performed by the CNR unit, in collaboration with the Center for Instrument Sharing (CISUP) of the University of Pisa.​

TUNA TOC - A.jpg

R. Sorodoc, P. De Vincenzi,

ACS Appl. Mater. Interfaces 16, 47 (2024)

The growth and the structural characterization of the NWs performed at the CNR unit is cross-correlated to advanced optical spectroscopy experiments (inelastic light scattering and photoluminescence) carried out at Sapienza University. The optical measurements are performed also with a photon-correlation setup to probe the properties of the grown QDs.

The close synergy of the two units allows a continuous flow of samples and information. In this way, a full picture of the structural, electronic, and optical properties of the QDs and SLs in NWs is achieved and controllably tuned.

 

Single QDs in NWs with high brightness and low multi-photon emission probability are being realized within this project, as well SLs with a tunable period, in order to determine the new type of band alignment arising in the SL and show the potential of these SLs for NW-based optoelectronic applications such as photodetectors. ​

 

Furthermore, NWs with GaAsP (with varying concentrations of As and P) in the wurtzite phase were created to study the new optical and electronic properties of the material in this new crystalline phase. The results of this study are then used as a starting point to better understand the effects of quantum confinement in the previously mentioned samples.

Team members:

  • Dr. Valentina Zannier, CNR researcher

  • Prof. Marta De Luca, Sapienza University professor

  • Prof. Lucia Sorba, CNR research director

  • Robert Andrei Sorodoc, CNR fellow

  • Paolo De Vincenzi, PhD student of Sapienza University

  • Giada Bucci, PhD student of Scuola Normale Superiore

Publications:

  1. Tunable GaAsxP1-x quantum dot emission in wurtzite GaP Nanowires. R. Andrei Sorodoc+, P. De Vincenzi+, A. Sagar Sharma, G. Bucci, M. Roggi, E. Mugnaioli, L. Sorba, M. De Luca and V. Zannier (+ equal contribution). ACS Appl. Mater. Interfaces 16, 47 (2024)

prin.bmp
bottom of page