Synergistic Boron Doping of Semiconductor and Dielectric Layers for High-Performance Metal Oxide Transistors: Interplay of Experiment and Theory


We report the results of a study to enhance metal oxide (MO) thin-film transistor (TFT) performance by doping both the semiconductor (In2O3) and gate dielectric (Al2O3) layers with boron (yielding IBO and ABO, respectively) and provide the first quantitative analysis of how B doping affects charge transport in these MO dielectric and semiconducting matrices. The impact of 1-9 atom % B doping on MO microstructure, morphology, oxygen defects, charge transport, and dielectric properties is analyzed together, in detail, by complementary experimental (microstructural, electrical) and theoretical (ab initio MD, DFT) methods. The results indicate that B doping frustrates In2O3 crystallization while suppressing defects responsible for electron trapping and carrier generation. In the adjacent Al2O3 dielectric, B doping increases the dielectric constant and refractive index while reducing leakage currents. Furthermore, optimized solution-processed TFTs combining IBO channels with 6 atom % B and ABO dielectrics with 10 atom % B exhibit field effect mobilities as high as 11 cm2 V-1 s-1, current on/off ratios > 105, threshold voltages = 0.6 V, and superior bias stress durability.



Research Center/Lab(s)

Center for High Performance Computing Research


The authors thank US-Israel Binational Science Foundation (BSF) (AGMT-2012250///02), ONR (MURI N00014-11-1-0690), the Northwestern U. MRSEC (NSF DMR-1720139), and Flexterra Corp. for support of this research. J.E.M. thanks the NSF-DMREF program (DMR-1729779) and XSEDE (DMR-080007) for support.

International Standard Serial Number (ISSN)

0002-7863; 1520-5126

Document Type

Article - Journal

Document Version


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© 2018 American Chemical Society (ACS), All rights reserved.

Publication Date

03 Oct 2018