Study On The Performance Of Ternary Bulk Heterojunction Wide-spectrum Organic Photodetector Based On P3HT:IEICO-4F System

In recent years,organic photodetectors have become a research hotspot due to their advantages of flexible large-area preparation,light weight,adjustable spectral response and low production cost.The study on organic photodetectors focuses on adjusting the spectral response bandwidth to achieve narrow-band or wide-band response.Recently,ultraviolet?UV?-visible?Vis?,infrared?NIR?high sensitivity of the wide spectrum of organic photoelectric detector because of its in chemical/biological sensor,night vision and huge potential application in the field of optical communication and so on,widely followed,among them,the ternary system is to improve the wide spectrum of organic photoelectric detector performance of a simple and effective way.Based on this,the novel P3HT:IEICO-4F binary wide-spectrum organic photodetectors were respectively doped with fullerene material PC₇₁BM and conjugated polymer material PTB7 as the third component,and the influence of the third component on the device performance was studied by regulating the proportion of doping material in the active layer.The specific research contents are as follows:1.The effect of PC₇₁BM doped with fullerene on device performance was studied.The fabricated OPD exhibited a high detectivity?D*?of 1.35×10¹² Jones at 805 nm by adding 10 wt%PC₇₁BM,which is 1.5 folds higher than it from the control system.The performance improvement is mainly due to the increase of light absorption in the short-wavelength range and the alignment of cascade energy levels to improve light absorption and exciton utilization.By adjusting the proportion of PC₇₁BM receptor,the active layer morphology was optimized to effectively improve the charge transfer and mobility of the device and inhibit the bimolecular recombination.2.The effect of conjugated polymer PTB7 on the device performance was investigated.When the adding ratio of PTB7 is 5wt%,the D*value is 1.2?10¹² Jones.The prepared P3HT:PTB7:IEICO-4F ternary wide-spectrum organic photodetector has the best performance and the detection rate is 1.6 times that of the secondary components.The main reason for the performance improvement is that the PTB7 material complements the device's 600-800 nm band light absorption,utilizes the Forster energy transfer from P3HT to PTB7,and balances the electron and hole mobility.In addition,the addition of PTB7 optimizes the surface morphology of the active layer.The non-twinned recombination process in the active layer is inhibited to ensure that carriers can be transmitted and collected effectively.In summary,the use of PC₇₁BM or polymer PTB7 as the third element added P3HT:IEICO-4F system can effectively improve the performance of wide-spectrum organic photodetectors.This work provides an effective method for the realization of a new high-performance three-component wide-spectrum organic photodetector.