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Quantum Confinement and Thickness‐Dependent Electron Transport in Solution‐Processed In 2 O 3 Transistors
Author(s) -
Isakov Ivan,
Faber Hendrik,
Mottram Alexander D.,
Das Satyajit,
Grell Max,
Regoutz Anna,
Kilmurray Rebecca,
McLachlan Martyn A.,
Payne David J.,
Anthopoulos Thomas D.
Publication year - 2020
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.202000682
Subject(s) - materials science , transistor , quantum dot , electron mobility , semiconductor , field effect transistor , scattering , condensed matter physics , electron , optoelectronics , induced high electron mobility transistor , charge carrier , optics , physics , voltage , quantum mechanics
The dependence of charge carrier mobility on semiconductor channel thickness in field‐effect transistors is a universal phenomenon that has been studied extensively for various families of materials. Surprisingly, analogous studies involving metal oxide semiconductors are relatively scarce. Here, spray‐deposited In 2 O 3 layers are employed as the model semiconductor system to study the impact of layer thickness on quantum confinement and electron transport along the transistor channel. The results reveal an exponential increase of the in‐plane electron mobility ( µ e ) with increasing In 2 O 3 thickness up to ≈10 nm, beyond which it plateaus at a maximum value of ≈35 cm 2 V −1 s −1 . Optical spectroscopy measurements performed on In 2 O 3 layers reveal the emergence of quantum confinement for thickness <10 nm, which coincides with the thickness that µ e starts deteriorating. By combining two‐ and four‐probe field‐effect mobility measurements with high‐resolution atomic force microscopy, it is shown that the reduction in µ e is attributed primarily to surface scattering. The study provides important guidelines for the design of next generation metal oxide thin‐film transistors.