厚度对BiFeO3薄膜的光伏性能的影响.docVIP

  Effect of thickness on the photovoltaic properties of BiFeO3 thin film#  5 10 15 20 25 30 35 40 ZHOU Yine1, TAN Xinyu2, YU Benfang1, LIU Li1, YUAN Songliu1, JIAO Weihong1** (1. School of Physics, Huazhong University of Science and Technology, 430074; 2. Research Institute for New Energy, China Three Gorges University, 443002) Abstract: We study the effects of film thickness on lattice parameters, direct band gap and photovoltaic outputs in the sol–gel derived BiFeO3 thin films. With the film thickness change, the great transitions have taken place in the preferred orientation and lattice parameters. Furthermore, the photovoltaic outputs are significantly dependent on the film thickness. The results show that the open circuit voltage gradually increases and the short circuit current reciprocally decreases with the increase of film thickness. Key words: Photovoltaic properties; BiFeO3 film; Film thickness 0 Introduction The photovoltaic properties of ferroelectric materials have become a research hotspot on account of the potential application values for photovoltaic cell and photo-driven actuator or optical sensor in micro-electromechanical systems. It is found that BiFeO3 (BFO) exhibits high sensitivity and fast response to the visible light due to the band gap in the visible range [1,2]. Furthermore, BFO is the single-phase multiferroic material at room temperature owing to its high ferroelectric Curie temperature of 1100 K and high antiferromagnetic Neel temperature of 640 K. So the ferroelectric BFO can respond to solar illumination to generate the steady-state photovoltage and photocurrent because of the separation and movement of photo-induced electron-hole pairs by the internal self-polarization field. In recent years, photovoltaic effects have been reported in single crystalline BFO bulk, BFO ceramics and BFO thin films [3-5]. In particular, a very attractive feature of ferroelectric photovoltaic materials is their tunable photovoltaic outputs with the