ALD Oxides-Based n-i-p Heterostructure Light Emitting Diodes
S. Gieraltowska, L. Wachnicki, M. Godlewski
Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
Received: July 27, 2018
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The aim of this work was an analysis of structural, electrical and optical properties of n-type ZnO/i/p-type (called as n-i-pd) GaN heterostructure with interlayer between these semiconductors. Such junctions are promising structures for light-emitting diodes, light detectors in the range of ultraviolet radiation and photovoltaic cells. This work concentrates on the investigation of the influence of oxide interlayers in optoelectronic structures, and optimization of growth parameters (in the atomic layer deposition - ALD process) of all oxide layers. Composition of HfO2, TiO2, ZrO2 and Al2O3 films was also optimized. The layers were used as intrinsic barriers to improve the performance and realize color shift of the n-ZnO/p-GaN heterojunction LEDs. The rectification ratio of n-i-p junctions was Ion/Ioff=1×102-103 for the voltage of 20 V. The color emission of these devices was adjusted from violet to white light in a room temperature depending on the growth parameters and composition of the ALD oxide layers.

PACS numbers: 79.60.Jv, 73.40.Lq, 81.15.-z