Details

Autor(en) / Beteiligte

• Budde, Melanie

Titel

Heteroepitaxy, Surface- and Bulk Hole Transport, and Application of the p-Type Semiconducting Oxides NiO and SnO

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2020

Link zum Volltext

• ProQuest

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• The present work is a comprehensive study on molecular beam epitaxy (MBE) growth and measured Seebeck coefficients and hole transport properties of p‑type oxides, a class of materials combining optical transparency and tunable conductivity. In particular, nickel oxide (NiO) and tin monoxide (SnO) were grown by plasma-assisted MBE using a metal effusion cell and an oxygen plasma. For the NiO growth, the growth limits at high temperatures were mainly determined, which depend on the substrate stability in the case of magnesium oxide and gallium nitride. The possibility of quality assessment using Raman spectroscopy for sodium chloride structures is shown. Investigation of NiO doping by surface acceptors and the associated surface hole enhancement layer reveals a new doping possibility for p-type oxides in general. The metastable phase of the SnO is stabilized using PAMBE using known growth kinetics of tin dioxide and various in‑situ methods, the application-relevant thermal stability is investigated. Subsequent ex‑situ characterizations by XRD and Raman spectroscopy identify the small growth window for the epitaxial growth of SnO. Electrical measurements confirm the p-type charge carriers with promising hole mobilities, which are also accessible for Hall measurements. Temperature-dependent Hall measurements show a band-like transport which indicates a high quality of the grown layers. The functionality of the grown layers is proven by various applications. For example, pn‑heterojunctions were obtained by the heteroepitaxial growth of SnO layers on a gallium oxide substrate. The first reported SnO-based pn junctions with an ideality factor below two have been achieved.