TY - JOUR
T1 - Mapping Charge Recombination and the Effect of Point-Defect Insertion in Nanowire Heterojunctions
AU - Zutter, Brian T.
AU - Kim, Hyunseok
AU - Hubbard, William A.
AU - Ren, Dingkun
AU - Mecklenburg, Matthew
AU - Huffaker, Diana
AU - Regan, B. C.
N1 - Publisher Copyright:
© 2021 American Physical Society
PY - 2021/10
Y1 - 2021/10
N2 - 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.
AB - 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.
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U2 - 10.1103/PhysRevApplied.16.044030
DO - 10.1103/PhysRevApplied.16.044030
M3 - Article
AN - SCOPUS:85118583211
SN - 2331-7019
VL - 16
JO - Physical Review Applied
JF - Physical Review Applied
IS - 4
M1 - 044030
ER -