Directly Linking Low-Angle Grain Boundary Misorientation to Device Functionality for GaAs Grown on Flexible Metal Substrates

Harvey Guthrey, Jonathan Poplawsky, Pavel Dutta, Donovan Leonard, Wei Guo, Mitsul Kacharia, Monika Rathi, Devendra Khatiwada, Carlos Favela, Sicong Sun, Chuanze Zhang, Seth Hubbard, Venkat Selvamanickam

Research output: Contribution to journalArticlepeer-review

5 Scopus Citations


A new growth method to make highly oriented GaAs thin films on flexible metal substrates has been developed, enabling roll-to-roll manufacturing of flexible semiconductor devices. The grains are oriented in the <001> direction with <1° misorientations between them, and they have a comparable mobility to single-crystalline GaAs at high doping concentrations. At the moment, the role of low-angle grain boundaries (LAGBs) on device performance is unknown. A series of electron backscatter diffraction (EBSD) and cathodoluminesence (CL) studies reveal that increased doping concentrations decrease the grain size and increase the LAGB misorientation. Cross-sectional scanning transmission electron microscopy (STEM) reveals the complex dislocation structures within LAGBs. Most importantly, a correlative EBSD/electron beam-induced current (EBIC) experiment reveals that LAGBs are carrier recombination centers and that the magnitude of recombination is dependent on the degree of misorientation. The presented results directly link increased LAGB misorientation to degraded device performance, and therefore, strategies to reduce LAGB misorientations and densities would improve highly oriented semiconductor devices.

Original languageAmerican English
Pages (from-to)10664-10672
Number of pages9
JournalACS Applied Materials and Interfaces
Issue number9
StatePublished - 4 Mar 2020

Bibliographical note

Publisher Copyright:
Copyright © 2020 American Chemical Society.

NREL Publication Number

  • NREL/JA-5K00-76213


  • cathodoluminescence
  • electron beam-induced current
  • flexible semiconductors
  • photovoltaics
  • scanning transmission electron microscopy


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