High-mobility p-channel wide-bandgap transistors based on hydrogen-terminated diamond/hexagonal boron nitride heterostructures

Reliable p-doped hexagonal boron nitride (h-BN) could enable wide bandgap optoelectronic devices such as deep ultra-violet light emitting diodes (UV LEDs), solar blind photodiodes and neutron detectors. We report the study of Mg in h-BN layers as well as Mg h-BN/AlGaN heterostructures. Mg incorporation in h-BN was studied under different biscyclopentadienyl-magnesium (Cp2Mg) molar flow rates. 2θ-ω x-ray diffraction scans clearly evidence a single peak, corresponding to the (002) reflection plane of h-BN with a full-width half maximum increasing with Mg incorporation in h-BN. For a large range of Cp2Mg molar flow rates, the surface of Mg doped h-BN layers exhibited characteristic pleats, confirming that Mg doped h-BN remains layered. Secondary ion mass spectrometry analysis showed Mg incorporation, up to 4 × 1018 /cm3 in h-BN. Electrical conductivity of Mg h-BN increased with increased Mg-doping. Heterostructures of Mg h-BN grown on n-type Al rich AlGaN (58% Al content) were made with the intent of forming a p-n heterojunction. The I-V characteristics revealed rectifying behavior for temperatures from 123 to 423 K. Under ultraviolet illumination, photocurrent was generated, as is typical for p-n diodes. C-V measurements evidence a built-in potential of 3.89 V. These encouraging results can indicate p-type behavior, opening a pathway for a new class of wide bandgap p-type layers.

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NUCLEATE POOL BOILING AND CONDENSATION HEAT TRANSFER CHARACTERISTICS OF HEXAGONAL BORON NITRIDE/DICHLOROMETHANE NANOFLUID

Heat Transfer Research ◽

10.1615/heattransres.2020034308 ◽

2020 ◽

Vol 51 (11) ◽

pp. 1043-1059

Author(s):

Erdem Çiftçi ◽

Adnan Sözen

Keyword(s):

Heat Transfer ◽

Boron Nitride ◽

Hexagonal Boron Nitride ◽

Pool Boiling ◽

Condensation Heat Transfer ◽

Nucleate Pool Boiling ◽

Heat Transfer Characteristics ◽

Transfer Characteristics

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Marcus-Hush Theory Revealed by Electron Tunneling Through Hexagonal Boron Nitride

10.26434/chemrxiv.9275135.v1 ◽

2019 ◽

Author(s):

Matěj Velický ◽

Sheng Hu ◽

Colin R. Woods ◽

Peter S. Toth ◽

Viktor Zólyomi ◽

...

Keyword(s):

Electron Transfer ◽

Boron Nitride ◽

Electron Tunneling ◽

Hexagonal Boron Nitride ◽

Large Body ◽

Liquid Solution ◽

Limiting Current ◽

Electron Transfer Rate Constant ◽

Electrochemical Parameters ◽

Voltammetric Measurements

Marcus-Hush theory of electron transfer is one of the pillars of modern electrochemistry with a large body of supporting experimental evidence presented to date. However, some predictions, such as the electrochemical behavior at microdisk electrodes, remain unverified. Herein, we present a study of electron tunneling across a hexagonal boron nitride barrier between a graphite electrode and redox levels in a liquid solution. This was achieved by the fabrication of microdisk electrodes with a typical diameter of 5 µm. Analysis of voltammetric measurements, using two common redox mediators, yielded several electrochemical parameters, including the electron transfer rate constant, limiting current, and transfer coefficient. They show a significant departure from the Butler-Volmer behavior in a clear manifestation of the Marcus-Hush theory of electron transfer. In addition, our system provides a novel experimental platform, which could be applied to address a number of scientific problems such as identification of reaction mechanisms, surface modification, or long-range electron transfer.

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