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.

通过利用外部应变感应的正或负压电电荷（压电电荷）来调节电荷载流子的产生，分离，传输和重组，已广泛引入了压电效应，以改善光电器件的性能。但是，直到今天，在大多数情况下，只有具有一种极性的压电电荷（即，正数或负数）被有效利用。在这项工作中，我们制作了n-Si / n-ZnO / p-PEDOT：PSS三层异质结光电探测器（HPD），并同时利用正负压电电荷对压电光电效应对其性能进行了系统研究。第一次。可以极大地优化对405和648 nm激光照射的光响应性，与在无应变条件下相比，分别提高了3000％和1800％以上。通过仔细分析HPD的能带图中的应变引起的变化，系统地研究了深入的工作机制，并通过有限元分析仿真进一步验证了该机制。