Superior ferroelectric photovoltaic properties in Fe -modified (Pb,La)(Zr,Ti)O3 thin film by improving the remnant polarization and reducing the bandgap
Superior ferroelectric photovoltaic properties in Fe -modified (Pb,La)(Zr,Ti)O3 thin film by improving the remnant polarization and reducing the bandgap
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通过改善剩余极化和减小带隙，Fe 改性 (Pb,La)(Zr,Ti)O3 薄膜具有优异的铁电光伏性能
DOI：
10.1016/j.ceramint.2020.03.040
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发表时间：
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通讯作者：
Yunbin He
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文献类型：
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作者：
Guang Chen;Ying Zhang;Qingfeng Zhang;Yinmei Lu;Yunbin He
为了开发具有高功率转换效率的铁电光伏器件，铁电材料必须同时具有较大的剩余极化和较窄的带隙，以便有效地分离光生载流子并吸收更多的阳光。基于这一思路，本文将Fe3+引入到Pb0·93La0·07(Zr0·6Ti0.4)0.9825 o3铁电薄膜中，增加了薄膜的残余极化，减小了薄膜的带隙。为此，我们制备了Fe3+掺杂的Pb0·93La0·07(z0·6Ti0.4)0.9825 o3薄膜光伏器件。实验结果表明：随着Fe3+加入量的增加，薄膜的残余极化先提高，在Fe3+含量为4.8 mol%时达到最大值50 μC/cm2，然后逐渐减小，带隙不断减小；此外，在负极性电压下，器件的短路电流和开路电压比在正极性电压下的短路电流和开路电压更大，这是由于铁电薄膜的残余极化产生的去极化电场与肖特基势垒引起的内置电场方向相同。在该器件中，Fe3+用量为4.8 mol%，极化电压为- 5 V，开路电压高达- 0.55 V，短路电流高达0.4 μA/cm2，获得了最优的光伏性能。这是由于该装置的太阳光吸收性能和光生载流子分离能力的提高。本研究为设计和制备具有高功率转换效率的铁电光伏器件提供了新的思路。
In order to develop ferroelectric photovoltaic devices with high power conversion efficiency, ferroelectric materials must have simultaneously large remnant polarization and narrow band gap so as to efficiently separate photo-generated carriers and absorb more sunlight. Based on this idea, in this report, we introduce Fe3+into Pb0·93La0·07(Zr0·6Ti0.4)0.9825O3ferroelectric thin film to increase the remnant polarization and decrease the band gap of the thin film. In doing so, we prepare Fe3+doping Pb0·93La0·07(Zr0·6Ti0.4)0.9825O3thin-film based photovoltaic devices. The experimental results indicate that with increasing the Fe3+amount, the remnant polarization of the film first improves to the maximum value of 50 μC/cm2at the 4.8 mol% Fe3+content and then reduces gradually, while the band gap continuously decreases. In addition, at a negative poling voltage, the device exhibits larger short-circuit current and open-circuit voltage in comparison with those obtained at the positive poling voltage, which is attributed to the depolarization electric field originating from the remnant polarization of ferroelectric thin films in the same direction as the built-in electric field caused by the Schottky barrier. In this report, the most superior photovoltaic performances with the open-circuit voltage of as large as −0.55 V and short-circuit current of as high as 0.4 μA/cm2are obtained in the device with 4.8 mol% Fe3+amount and at −5 V poling voltage. This is on account of the improved sunlight absorbing properties and photo-generated carriers separation ability of the device. This work provides a novel idea for designing and preparing ferroelectric photovoltaic devices with high power conversion efficiency.