Mapping Charge Recombination and the Effect of Point-Defect Insertion in Nanowire Heterojunctions

Brian T. Zutter, Hyunseok Kim, William A. Hubbard, Dingkun Ren, Matthew Mecklenburg, Diana Huffaker, B. C. Regan

Research output: Contribution to journalArticlepeer-review

Abstract

Electronic devices are extremely sensitive to defects in their constituent semiconductors, but locating electronic point defects in bulk semiconductors has previously been impossible. Here we apply scanning transmission electron microscopy (STEM) electron-beam-induced current (EBIC) imaging to map electronic defects in a nanowire Schottky diode. Imaging with a nondamaging 80 or 200 kV STEM acceleration potential reveals a minority-carrier diffusion length that decreases near the surface of the hexagonal nanowire, thereby demonstrating that the device’s charge collection efficiency (CCE) is limited by surface defects. Imaging with a 300 keV STEM beam introduces vacancy-interstitial (or Frenkel) defects in the that increase carrier recombination and reduce the CCE of the diode. We create, locate, and characterize a single insertion event, determining that a defect inserted 7 nm from the Schottky interface broadly reduces the CCE by across the entire nanowire device. Variable-energy STEM EBIC imaging thus allows both benign mapping and pinpoint modification of a device’s electron-hole-recombination landscape, enabling controlled experiments that illuminate the impact of both extended (one- and two-dimensional) and point (zero-dimensional) defects on semiconductor device performance.

Original languageEnglish (US)
Article number044030
JournalPhysical Review Applied
Volume16
Issue number4
DOIs
StatePublished - Oct 2021
Externally publishedYes

ASJC Scopus subject areas

  • General Physics and Astronomy

Fingerprint

Dive into the research topics of 'Mapping Charge Recombination and the Effect of Point-Defect Insertion in Nanowire Heterojunctions'. Together they form a unique fingerprint.

Cite this