{"title":"Mobility and conductivity of laser-generated e-h plasmas in direct-gap nanowires","authors":"Jeremy R. Gulley, Rachel Cooper, Ethan Winchester","doi":"10.1016/j.photonics.2024.101259","DOIUrl":null,"url":null,"abstract":"<div><p>This article examines the role of field strength, frequency, and many-body scattering during the ultrafast optoelectronic response in a direct-gap semiconductor nanowire using numerical simulation. Following resonant laser excitation, an AC or bias DC field perturbs the 1D <em>e-h</em> plasma as it relaxes by carrier-phonon and Coulomb scattering. For bias DC fields, the laser-excited carrier distributions evolve to a static non-equilibrium from which a stable DC mobility is calculated. Carrier-phonon collisions contain the <em>e-h</em> carriers near energy minima for fields of 0.5 kV/cm or less, while the Coulomb collisions redistribute some electrons across the Brillouin zone where they drift into other band structure energy minima and are there contained by phonon scattering. This behavior results in carrier mobilities with a field-strength dependence specific to a 1D solid. For AC probe fields, the analyze the resulting frequency-dependent conductivity for frequencies between the plasmon frequency and interband resonance. In all cases, we compare results to standard-conductivity models by calculating distribution-averaged collision rates and times, and show how, unlike in the bulk, these quantities for the nanowire are strongly dependent on both field magnitude and frequency.</p></div>","PeriodicalId":49699,"journal":{"name":"Photonics and Nanostructures-Fundamentals and Applications","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Photonics and Nanostructures-Fundamentals and Applications","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1569441024000348","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
This article examines the role of field strength, frequency, and many-body scattering during the ultrafast optoelectronic response in a direct-gap semiconductor nanowire using numerical simulation. Following resonant laser excitation, an AC or bias DC field perturbs the 1D e-h plasma as it relaxes by carrier-phonon and Coulomb scattering. For bias DC fields, the laser-excited carrier distributions evolve to a static non-equilibrium from which a stable DC mobility is calculated. Carrier-phonon collisions contain the e-h carriers near energy minima for fields of 0.5 kV/cm or less, while the Coulomb collisions redistribute some electrons across the Brillouin zone where they drift into other band structure energy minima and are there contained by phonon scattering. This behavior results in carrier mobilities with a field-strength dependence specific to a 1D solid. For AC probe fields, the analyze the resulting frequency-dependent conductivity for frequencies between the plasmon frequency and interband resonance. In all cases, we compare results to standard-conductivity models by calculating distribution-averaged collision rates and times, and show how, unlike in the bulk, these quantities for the nanowire are strongly dependent on both field magnitude and frequency.
期刊介绍:
This journal establishes a dedicated channel for physicists, material scientists, chemists, engineers and computer scientists who are interested in photonics and nanostructures, and especially in research related to photonic crystals, photonic band gaps and metamaterials. The Journal sheds light on the latest developments in this growing field of science that will see the emergence of faster telecommunications and ultimately computers that use light instead of electrons to connect components.