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Challenges in Simultaneous Microstructuring and Hyperdoping of Germanium with Ultrafast Laser
Tekijät: Gnatyuk, Dmytro; Hamed, Sara; Ebrahimzadeh, Masoud; Liu, Hanchen; Vahanissi, Ville; Laukkanen, Pekka; Savin, Hele; Liu, Xiaolong
Kustantaja: Wiley
Julkaisuvuosi: 2026
Lehti: physica status solidi (a)
Artikkelin numero: e202500987
Vuosikerta: 223
Numero: 8
ISSN: 1862-6300
eISSN: 1862-6319
DOI: https://doi.org/10.1002/pssa.202500987
Julkaisun avoimuus kirjaamishetkellä: Avoimesti saatavilla
Julkaisukanavan avoimuus : Osittain avoin julkaisukanava
Verkko-osoite: https://doi.org/10.1002/pssa.202500987
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/523237968
Rinnakkaistallenteen lisenssi: CC BY
Rinnakkaistallennetun julkaisun versio: Kustantajan versio
Germanium's compatibility with Complementary Metal-Oxide-Semiconductor (CMOS) and strong near-infrared response make it an attractive platform for infrared photonics, but its intrinsic material properties hinder straightforward extension of absorption beyond the band edge. In this perspective, we synthesize recent and new experiments and analyses on femtosecond-laser approaches that attempt to combine surface microstructuring and hyperdoping of Ge in a single step. We argue that, unlike silicon, Ge's high optical absorption at visible/green wavelengths, shallow energy deposition, lower melting point, and reduced thermal conductivity favor intense localized heating, evaporation, and redeposition-conditions that both produce high baseline sub-bandgap absorption from damage and prevent effective incorporation of thin-film dopant precursors. In a case example, Ti shows only trace incorporation from qualitative measurements. We discuss why laser-induced structural disorder, rather than stable deep dopant incorporation, dominates the optical response, and we outline practical pathways forward: exploring longer wavelengths or gas-phase chemistries, applying separate in situ heating, or decoupling texturing from heavy doping.
Ladattava julkaisu This is an electronic reprint of the original article. |
Julkaisussa olevat rahoitustiedot:
This study was supported by Research Council of Finland through project HyperGer (354199), NIR-REM (365427), and PREIN (346529).