Optoelectronic properties of ZnO/ZnMgO multiple quantum wells in ZnMgO nanocolumns grown on Si (111)

• Published in: Journal of alloys and compounds Vol. 717; pp. 41 - 47
• Main Authors: Pietrzyk, M.A., Placzek-Popko, E., Paradowska, K.M., Zielony, E., Stachowicz, M., Reszka, A., Kozanecki, A.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.09.2017; Elsevier BV
• Subjects: Cathodoluminescence; Chemical sensors; Conduction bands; Cross-sections; Current voltage characteristics; Deep level transient spectroscopy; Detectors; Diodes; Electric potential; Electric properties; Electrical measurement; Electronic properties; Epitaxial growth; Ground state; Light emitting diodes; Molecular beam epitaxy; Optical properties; Optical spectroscopy; Optoelectronics; Oxide materials; Photoluminescence; Quantum wells; Semiconductors; Silicon substrates; Spectroscopic analysis; Superlattices; Zinc oxide; Optical spectroscopy; Electronic properties; Oxide materials; Optical properties
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.05.090

Superlattice structures formed using the II-VI family of semiconductors have attracted a great deal of attention due to some unique properties (chemical sensors, UV detectors, lasers, white LED). We present a comparison of optical and electrical measurements of 10-period ZnO/ZnMgO multiple quantum wells (MQWs). The structures have been fabricated on (111) Si by molecular beam epitaxy grown at very high temperatures. The optical properties were analyzed by photoluminescence and cathodoluminescence techniques. Cross-sectional SEM-CL mapping shows that the ZnO/ZnMgO multiple quantum wells are located in ZnMgO nanocolumns. Based on these structures, diodes were processed and characterized by current-voltage (I-V), capacitance-voltage and deep level transient spectroscopy techniques (DLTS). I-V measurements confirm that in both diodes, deep traps govern the conduction mechanisms at a forward bias. DLTS studies yield signatures of these traps as well as those related to the presence of QWs. In particular, DLTS results let us estimate the distance of 30 meV from the QW ground state to the barrier conduction band. •The MQWs reveal excitonic near-band edge emission at low and RT in the PL and CL.•Cross-sectional SEM-CL mapping shows that the ZnO/ZnMgO MQWs are located in ZnMgO nanocolumns.•The I-V curves confirm the presence of trap states at the n-ZnO/p-Si interface.•DLTS studies yield signatures of the traps as well as those related to the presence of QWs.