TY - JOUR
T1 - Metal-insulator transition in a semiconductor nanocrystal network
AU - Greenberg, Benjamin L.
AU - Robinson, Zachary L.
AU - Ayino, Yilikal
AU - Held, Jacob T.
AU - Peterson, Timothy A.
AU - Andre Mkhoyan, K.
AU - Pribiag, Vlad S.
AU - Aydil, Eray S.
AU - Kortshagen, Uwe R.
N1 - Publisher Copyright:
Copyright © 2019 The Authors,
PY - 2019/8/23
Y1 - 2019/8/23
N2 - Many envisioned applications of semiconductor nanocrystals (NCs), such as thermoelectric generators and transparent conductors, require metallic (nonactivated) charge transport across an NC network. Although encouraging signs of metallic or near-metallic transport have been reported, a thorough demonstration of nonzero conductivity, σ, in the 0 K limit has been elusive. Here, we examine the temperature dependence of σ of ZnO NC networks. Attaining both higher σ and lower temperature than in previous studies of ZnO NCs (
T as low as 50 mK), we observe a clear transition from the variable-range hopping regime to the metallic regime. The critical point of the transition is distinctly marked by an unusual power law close to σ ∝
T
1/5. We analyze the critical conductivity data within a quantum critical scaling framework and estimate the metal-insulator transition (MIT) criterion in terms of the free electron density,
n, and interparticle contact radius, ρ.
AB - Many envisioned applications of semiconductor nanocrystals (NCs), such as thermoelectric generators and transparent conductors, require metallic (nonactivated) charge transport across an NC network. Although encouraging signs of metallic or near-metallic transport have been reported, a thorough demonstration of nonzero conductivity, σ, in the 0 K limit has been elusive. Here, we examine the temperature dependence of σ of ZnO NC networks. Attaining both higher σ and lower temperature than in previous studies of ZnO NCs (
T as low as 50 mK), we observe a clear transition from the variable-range hopping regime to the metallic regime. The critical point of the transition is distinctly marked by an unusual power law close to σ ∝
T
1/5. We analyze the critical conductivity data within a quantum critical scaling framework and estimate the metal-insulator transition (MIT) criterion in terms of the free electron density,
n, and interparticle contact radius, ρ.
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U2 - 10.1126/sciadv.aaw1462
DO - 10.1126/sciadv.aaw1462
M3 - Article
C2 - 31467972
AN - SCOPUS:85071257199
SN - 2375-2548
VL - 5
JO - Science Advances
JF - Science Advances
IS - 8
M1 - eaaw1462
ER -