The understanding of bending strain effects on the performances of flexible organic phototransistors (FOPTs) is of great importance. In this manuscript, two kinds of FOPTs- single layer of copper phthalocyanine (CuPc) (SL-FOPTs) and hybrid planar bulk-heterojunction of CuPc/CuPc:PTCDA (HPBHJ-OPTs) with PTCDA denotes 3,4,9,10-perylenete-acarboxylic dianhydride, with polyvinyl alcohol as the gate dielectric but different active layer, were fabricated and their strain dependent performances investigated, respectively. For SL-FOPTs, at a given light intensity, with the bending-strain increasing, the photocurrent increases at first, and then decreases after reaching a maximum. A crossover from positive to negative occurs in this process, and the critical strain at which the crossover occurs increases with the illumination light intensity. Different from the observation in SL-FOPTs, the I_dark∼strain curves in HPBHJ-FOPTs exhibit obtuse small peaks at low gate voltages of |V_g|≦10 V, and minimums at large gate voltages of |V_g|≧ 20 V. At large gate voltages with increasing bending strain, the photocurrent of HPBHJ-OPTs decreases and become negative (from positive) at first, with the decreasing rate nearly proportional to the gate voltage, and then increase after reaching a negative minimum. The physical origin of observed photocurrent crossover from positive to negative with increasing bending strain is discussed.

了解弯曲应变对柔性有机光电晶体管（FOPT）性能的影响非常重要。在本手稿中，两种FOPT：单层酞菁铜（CuPc）（SL-FOPT）和CuPc / CuPc：PTCDA（HPBHJ-OPTs）与PTCDA的混合平面体-异质结表示3,4,9,10-制备了以聚乙烯醇为栅极电介质但有源层不同的different-二羧酸二酐，并研究了其应变相关性能。对于SL-FOPT，在给定的光强度下，随着弯曲应变的增加，光电流首先增加，然后在达到最大值后减小。在此过程中发生从正到负的交叉，并且发生交叉的临界应变随着照明光强度而增加。我_暗〜应变在HPBHJ-FOPTs曲线在低栅极电压表现出钝角小峰| V _g |≤10V，并且在大栅极电压为|时最小值 V _g |≥20V。在较大的栅极电压下，随着弯曲应变的增加，HPBHJ-OPT的光电流首先下降，然后变为负值（从正值开始），下降率几乎与栅极电压成正比，然后在达到负的最小值。讨论了随着弯曲应变的增加，从正到负的光电流交叉的物理起源。