Near-infrared electroluminescence from light-emitting devices based on Nd-doped TiO2/ p +-Si heterostructures

• Published in: Applied physics letters Vol. 104; no. 20
• Main Authors: Yang, Yang, Lv, Chunyan, Zhu, Chen, Li, Si, Ma, Xiangyang, Yang, Deren
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 19-05-2014
• Subjects: Anatase; Applied physics; Electroluminescence; Energy transfer; Heterostructures; Light emission; Near infrared radiation; Neodymium; Rutile; Silicon; Titanium dioxide
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4879023

We report on near-infrared (NIR) electroluminescence (EL) from the light-emitting devices based on Nd-doped TiO2/p+-Si heterostructures. NIR emissions peaking at ∼910, 1090, and 1370 nm, originated from intra-4f transitions in Nd3+ ions, can be activated by a forward bias voltage as low as ∼5 V. Such NIR EL is triggered by the energy transferred from TiO2 host to Nd3+ ions. It is found that the coexistence of anatase and rutile phases in the TiO2 host enables the device to exhibit pronounced Nd-related EL without concurrent emission from the TiO2 host itself, quite other than the case of existing only anatase phase in TiO2 host. We tentatively suggest that the anatase/rutile interface states play important role in the energy transfer from TiO2 host to Nd3+ ions.