Photocarrier injection and photo-resistance in SrTiO3−δ/GaAs p-n junctions
Department of Physics, The University of Hong Kong - Pokfulam Road, Hong Kong
Received: 5 September 2012
Accepted: 14 November 2012
Heterojunctions composed of n-type oxygen-deficient SrTiO3−δ and p-type GaAs were fabricated using pulsed laser deposition method. The good crystallinity of SrTiO3−δ was confirmed by X-ray diffraction, reflection high-energy electron diffraction, and transmission electron microscopy. These heterojunctions exhibited excellent rectifying behavior from 40 K to room temperature. The photocarrier injection effect and a large photo-resistance were observed in a wide temperature range. The photo-resistance is nearly 100% at low temperatures and ∼40% at room temperature under −0.5 V bias. Strong dependences on both temperature and bias voltage were found as well, which might be understood by considering the band structure of the formed p-n junction.
PACS: 73.50.Pz – Photoconduction and photovoltaic effects / 81.15.Fg – Pulsed laser ablation deposition
© EPLA, 2012