Room-Temperature Persistent Photoconductivity in Barium Calcium Titanate
Room-Temperature Persistent Photoconductivity in Barium Calcium Titanate
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DOI：
10.1007/s11664-022-10205-9
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发表时间：
2023-01-16
影响因子：
2.1
通讯作者：
McCluskey, Matthew D.
中科院分区：
文献类型：
--
作者：
Ahmed, Syeed E.;Poole, Violet M.;McCluskey, Matthew D.
Ba1-xCaxTiO3(Ba1-xCaxTiO3，BCTO)在2%的氢气-Ar混合气体中进行了热处理，表现出室温持久的光电导性。选择退火气氛以产生可被光激发的替代氢杂质，从而导致PPC现象。在x=0.15的BCTO晶体中，PPC的阈值光子能量为2.7 eV，低于BaTiO_3和SrTiO_3晶体的阈值光子能量(2.9 eV)。中红外吸收的显著增加归因于自由载流子，与电阻的下降相关。这种效应在室温下持续数天。样品在空气中的退火消除了PPC，表明该过程是可逆的。
Barium calcium titanate (Ba1-xCaxTiO3, BCTO) annealed under a flowing humid 2% hydrogen-argon gas mixture exhibits room-temperature persistent photoconductivity (PPC). The annealing atmosphere was chosen to produce substitutional hydrogen impurities that can be photoexcited, leading to the PPC phenomenon. The threshold photon energy for PPC in a BCTO crystal with x = 0.15 is 2.7 eV, lower than that for BaTiO3 and SrTiO3 (2.9 eV). A significant increase in mid-infrared absorption, attributed to free carriers, was correlated with a drop in electrical resistance. This effect showed persistence for several days at room temperature. Annealing the sample in air erased the PPC, indicating that the process is reversible.