Depolarization electric field and poling voltage-modulated Pb,La(Zr,Ti)O3-based self-powered ultraviolet photodetectors |
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| Authors: | Ying Zhang Jian Chen Yixing Cai Qingfeng Zhang Yinmei Lu Haitao Huang Yunbin He |
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| Affiliation: | 1. Ministry of Education Key Laboratory of Green Preparation and Application for Functional Materials, Hubei Key Lab of Ferro & Piezoelectric Materials and Devices, Hubei Key Laboratory of Polymer Materials, School of Materials Science & Engineering, Hubei University, Wuhan, China;2. Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, China |
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| Abstract: | Traditional self-powered ultraviolet photodetectors, which are usually designed based on p-n junction interfacial effects, exhibit low responsivity and specific detectivity because the photogenerated electrons and holes cannot be separated effectively. Unlike wide band-gap semiconductor materials, ferroelectrics have large remnant polarization and thus high depolarization electric field throughout the whole bulk region, which can cause effective separation of photogenerated electrons and holes. Based on this, in this study, we prepare Pb0.93La0.07(Zr1-xTix)0.9825O3 (PLZT) ferroelectric thin films with large remnant polarization and self-powered ultraviolet photodetectors with Au/PLZT/FTO structure. The results indicate that the photoelectric response performances of the detectors improve as the remnant polarization of the PLZT thin film and positive poling voltage increase. By adjusting the Ti content, due to large remnant polarization of 47.4 μC/cm2 in the PLZT thin films with 80 mol% Ti, the corresponding photodetector exhibits the best self-powered ultraviolet photoelectric response with the high photo/dark current ratio of 2600, responsivity of 2.05 mA/W, specific detectivity of 5.45 × 1010 Jones, and fast response speed (rise time of 18 ms). These values are superior to those of recently reported self-powered ultraviolet photodetectors. |
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