III-V Nanowires for Optoelectronics

When III-V compound semiconductors are fabricated in the form of nanowires, many properties change compared to thin films and bulk crystals. The goal of this core research area is to inspire and demonstrate new functionalities for optoelectronic applications by employing III-V nanowires.

We investigate fundamental nanowire properties that are crucial for such applications. Our research also includes studies on nanowire synthesis, as the composition, doping, dimensions, and arrangement of the nanowires must be controlled to manipulate their properties. We grow both group-III-nitride and group III-arsenide nanowires by molecular beam epitaxy, but also pursue top-down approaches. With regard to nanowire properties, we are particularly interested in phenomena that are a direct consequence of the special wire-like shape and nanometric size and that are independent of the nanowire material. In addition, we process demonstrator devices and analyze the influence of nanowire properties on them. Of particular interest are advanced nanowire structures—such as bent nanowires—that enable functionalities that are completely unimaginable with conventional planar approaches.

The application prospects of the work in this core research area range from the photoelectrochemical conversion of carbon dioxide into valuable chemicals to the production of pseudo-substrates and piezoelectric power generation.

Scientific Highlights

PhD research introduces a new way to probe light absorption in semiconductor nanowires

New research based on the PhD thesis of Francisca Marin Largo, carried out within PDI’s Core Research Area III-V Nanowires for Optoelectronics, has been published in Advanced Optical Materials. The study presents a new optical approach to probing light absorption in semiconductor nanowires — a long-standing experimental challenge in nanoscale optoelectronics. More…

PDI Researchers Achieve Thick (In,Ga)N Layers with Uniform Composition and Low Dislocation Density Using MBE

A new study by researchers at the Paul-Drude-Institut für Festkörperelektronik (PDI), published in Journal of Physics D: Applied Physics, demonstrates a major advancement in the growth of high-quality indium gallium nitride (InₓGa₁₋ₓN) layers using plasma-assisted molecular beam epitaxy (MBE). More…

Epitaxy of highly dissimilar transition metal nitride-semiconductor heterostructures with low defect density

This study demonstrates twin-free epitaxial growth of rocksalt ScN on wurtzite GaN. Our approach opens a new route to combine wurtzite III-nitrides (AlN, GaN, InN) with rocksalt transition metal nitrides (ScN, ZrN, HfN, TiN, CrN, NbN) with unprecedented structural quality. This successful integration of transition metal nitrides on group III-nitrides with low defect densities offers new opportunities to enhance existing devices or develop innovative ones. More…

Third-party Funded Projects

Selected Publications

2026

Strain distribution in zinc-blende and wurtzite GaAs nanowires bent by a one-sided (In,Al)As stressor shell: Consequences for torsion, chirality, and piezoelectricity
Authors: Y. Hadjimichael, O. Brandt, C. Merdon, C. L. Manganelli, P. Farrell
Source: Phys. Rev. B, 113, 165303
DOI: 10.1103/pjq7-8gll
Combining metal dewetting and lateral etching for the scalable top-down fabrication of GaN nanowire arrays with independently tunable diameter and spacing
Authors: J. Kang, R. Jose, O. Brandt, L. Geelhaar
Source: ACS Appl. Eng. Mater.
DOI: 10.1021/acsaenm.5c01058

2025

Diameter dependence of light absorption in GaAs nanowires evidenced by photoluminescence spectroscopy
Authors: F. Marín Largo, I. Mohamed, O. Brandt, L. Geelhaar
Source: Adv. Opt. Mater., 14, 15, e03215
DOI: 10.1002/adom.202503215
Optical Response of Ultrathin GaP Nanoantenna with Zincblende-to-Wurtzite Crystal Phase Transitions
Authors: E. N. T. Diak, J. Lähnemann, A. Moréac, J.-P. Landesman, K. Loeto, R. R. LaPierre
Source: Cryst. Growth Des., 25, 9312-9321
DOI: 10.1021/acs.cgd.5c01111
From (In,Ga)N top-down nanowires to pseudo-substrates
Authors: J. Kang, H. Zhang, A. Campbell, J. Lähnemann, O. Brandt, L. Geelhaar
Source: Proc. SPIE, 13582, 135820B
DOI: 10.1117/12.3067374
Growth of compositionally uniform InxGa1-xN layers with low relaxation degree on GaN by molecular beam epitaxy
Authors: J. Kang, M. Gómez Ruiz, D. V. Dinh, A. Campbell, P. John, T. Auzelle, A. Trampert, J. Lähnemann, O. Brandt, L. Geelhaar
Source: J. Phys. D: Appl. Phys., 58, 14LT01
DOI: 10.1088/1361-6463/adb4e7

2024

Uniform large-area surface patterning achieved by metal dewetting for the top-down fabrication of GaN nanowire ensembles
Authors: J. Kang, R. Jose, M. Oliva, T. Auzelle, M. Gómez Ruiz, A. Tahraoui, J. Lähnemann, O. Brandt, L. Geelhaar
Source: Nanotechnology, 35, 375301
DOI: 10.1088/1361-6528/ad5682
Composition and optical properties of (In, Ga)As nanowires grown by group-III-assisted molecular beam epitaxy
Authors: M. Gómez Ruiz, A. Castro, J. Herranz, A. da Silva, P. John, A. Trampert, O. Brandt, L. Geelhaar, J. Lähnemann
Source: Nanotechnology, 35, 265702
DOI: 10.1088/1361-6528/ad375b
ScN/GaN(1-100): a new platform for the epitaxy of twin-free metal-semiconductor heterostructures
Authors: P. John, A. Trampert, D. V. Dinh, D. Spallek, J. Lähnemann, V. Kaganer, L. Geelhaar, O. Brandt, T. Auzelle
Published in: Nano Lett., 24, 6233
DOI: https://doi.org/10.1021/acs.nanolett.4c00659
AlN Nanowire-Based Vertically Integrated Piezoelectric Nanogenerators
Authors: N. Buatip, T. Auzelle, P. John, S. Rauwerdink, M. Sodhi, M. Salaün, B. Fernandez, E. Monroy, D. Mornex, C. R. Bowen, R. Songmuang
Published in: ACS Appl. Nano Mater., 7, 15798
DOI: https://doi.org/10.1021/acsanm.4c03075
Detection of an unintentional Si doping gradient in site-controlled GaN nanowires grown using a Si3N4 mask by spatially-resolved cathodoluminescence and Raman spectroscopy
Authors: Mikel Gómez Ruiz, Matt Brubaker, Kris Bertness, Alexana Roshko, Hans Tornatzky, Manfred Ramsteiner, Oliver Brandt, Jonas Lähnemann
Published in: APL Mater. 12, 101123
DOI: https://doi.org/10.1063/5.0233859