ZnO with p-Type Doping: Recent Approaches and Applications

Abstract

ZnO is a significant semiconductor material with the characteristics of direct band gap, large exciton binding energy, and easy growth of high-quality nanostructures, and it is widely used in various fields. However, obtaining high-quality p-type ZnO has become a significant obstacle to the wide application of ZnO. The research on p-ZnO started several decades ago and is regarded as the research focus. Many researchers have obtained high-quality p-ZnO by chemical vapor deposition (CVD) and physical vapor deposition (PVD). To obtain high-quality p-ZnO, researchers have used some “better” techniques to improve the crystal quality and mobility of p-ZnO, such as molecular beam epitaxy (MBE) and post-treatment. This review provides an overview of some methods for obtaining high-quality p-ZnO, such as increasing the acceptor concentration, shallowing acceptor energy levels, and reducing donor defects. In addition, we also review the applications of p-ZnO in LEDs, UV detectors, thin-film transistors, gas sensing, bionic materials, and other fields.

Investigation on Synaptic Adaptation and Fatigue in ZnO/HfZrO-Based Memristors under Continuous Electrical Pulse Stimulation

“…Electronics 2024, 13, x FOR PEER REVIEW 9 of 14 intrinsically tied to its oxygen levels, with increased oxygen correlating to diminished conductivity [49]. Applying a positive bias to the top electrode, where ZnO is more oxygen-rich, prompts the electrically induced migration of oxygen ions, condensing the highresistance, oxygen-rich ZnO layer and thus enhancing device conductivity [50]. Concurrently, the oxygen-deficient HfZrO layer undergoes polarization.…”

Inhibition of Oxygen Vacancy Derived from Donor Doping in Relaxor Ferroelectric Films for Improving Dielectric Energy Storage

“…6 The oxygen vacancy not only results in the p-type leakage conductivity and decreased E BDS but also depresses P max due to the domain wall pinning effect originated from the oxygen vacancy. Therefore, decreasing the oxygen vacancy concentration is an important means to enhance E BDS and P max simultaneously, 7,8 and it is also an important way to break through the adverse coupling of the two from another perspective.…”

Strain-Induced Valence Band Splitting Enabling Above-Bandgap Exciton Luminescence in Epitaxial Mg3N2 Thin Films

“…16 In the oxide class of materials, ZnO has a nearly comparable bandgap (∼3.37 eV) as GaN (∼3.4 eV), but a higher E b of ∼60 meV 10 presents itself as an alternative WBG semiconductor with enhanced luminescence efficiency. Nevertheless, the challenge persists in achieving high-quality p-type ZnO, 17 thereby limiting its applications and driving the search for superior alternative materials. Mg 3 N 2 , an II-nitride semiconductor, has attracted substantial interest and exhibits many of the necessary criteria for optoelectronic device applications.…”