Optimization of Si/ZnO/PEDOT: PSS tri-layer heterojunction photodetector by piezo-phototronic effect using both positive and negative piezoelectric charges
Optimization of Si/ZnO/PEDOT: PSS tri-layer heterojunction photodetector by piezo-phototronic effect using both positive and negative piezoelectric charges
复制标题
Si/ZnO/PEDOT：利用正负压电电荷的压电光电子效应优化 PSS 三层异质结光电探测器
DOI：
10.1016/j.nanoen.2018.03.025
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发表时间：
2018
期刊：
影响因子：
17.6
通讯作者：
He Yongning
中科院分区：
文献类型：
--
作者：
Li Fangpei;Peng Wenbo;Pan Zijian;He Yongning
压电光电子效应是利用外部应变诱导的正或负压电电荷（压电电荷）来调节载流子的产生、分离、输运和重组，从而提高光电器件的性能。然而，在大多数情况下，直到今天，只有一个极性的压电电荷（即，正或负）被有效利用。本文首次制备了n-Si/n-ZnO/p-PEDOT:PSS三层异质结光电探测器（HPD），并系统地研究了同时使用正负压电电荷的压电光电子效应对其性能的影响。对405 nm和648 nm激光的光响应性可以得到极大的优化，与无应变条件下相比，光响应性分别提高了3000%和1800%以上。通过仔细分析HPD能谱图的应变诱导变化，系统地研究了HPD的深入工作机理，并通过有限元仿真进一步验证了这一结论。本研究不仅提出了利用正负压电电荷通过压电光电子效应来优化HPD的性能，而且对两个极性相反的压电电荷如何在一个光电器件中协同工作提供了深入的理解，有望在未来的应用中提出将压电光电子效应引入三层/多层器件的想法。
Piezo-phototronic effect has been extensively introduced to improve the performances of optoelectronic devices by utilizing external-strain-induced positive or negative piezoelectric charges (piezo-charges) to modulate the generation, separation, transportation, and recombination of charge carriers. However, in most cases till today, only the piezo-charges with one polarity (i.e., positive or negative) are effectively utilized. In this work, we fabricated an n-Si/n-ZnO/p-PEDOT:PSS tri-layer heterojunction photodetector (HPD) and systematically investigated the piezo-phototronic effect on its performances simultaneously utilizing both positive and negative piezo-charges for the first time. The photoresponsivity to 405 and 648 nm laser illuminations can be gigantically optimized, with astonishing enhancement of over 3000% and 1800% compared to that under strain free condition, respectively. The in-depth working mechanisms is systematically investigated by carefully analyzing the strain-induced variations in energy band diagrams of the HPD, which is further validated by finite element analysis simulations. This work not only presents the utilization of both positive and negative piezo-charges to optimize the performances of HPD by the piezo-phototronic effect, but also provides a deep understanding of how the piezo-charges of two opposite polarities work together in one optoelectronic device, hopefully proposing the idea of introducing the piezo-phototronic effect into three-/multi-layer devices in future applications.