Research Of Semitransparent Organic Solar Cell Based On Pseudo-Planar Heterojunction

Transparent organic photovoltaics have great potential for applications in photovoltaic buildings and wearable devices.It is demonstrated that the power conversion efficiency and average visible light transmission show a better balance in pseudo-planar heterojunction structures than in bulk heterojunction structures.In this thesis,the effect of successive deposition of PM6 and Y6 at different substrate temperatures on device performance is investigated.After determining the appropriate temperature,the structure for constructing transparent organic solar cells is determined by optical simulation and pseudo-planar heterojunction transparent organic solar cells based on PM6/Y6 are constructed,and the effect of the feedthrough thickness ratio on pseudo-planar heterojunction transparent organic solar cells is investigated by optimizing the feedthrough thickness.solar cells by optimizing the feedthrough thickness.It was found that the devices obtained by successive deposition of PM6Y6 at low temperature(substrate temperature)showed opposite performance in the positive and negative structures.By controlling the substrate temperature and comparing the performance trend of the positive and negative devices prepared at different substrate temperatures,it was found that the performance of the negative devices showed a rising trend followed by a decreasing trend as the temperature decreased,and the negative devices showed the best performance at 15℃.The positive device shows the best performance at 35℃.The positive device shows the best performance at 35℃.We thus propose that at low temperatures,small molecule receptor Y6 is deposited to the bottom of the active layer by polymer PM6 and shows a vertical gradient concentration distribution,and this conjecture is confirmed by scanning electron microscopy energy spectrum analysis of cross sections.The pseudo-planar heterojunction device constructed by low-temperature sequential deposition has an open-circuit voltage of 0.80 V,a short-circuit current of 27.33 m A/cm~2,a fill factor of 64.3%,and an energy conversion efficiency of 14.40%,with a 7.11%performance improvement compared to the bulk heterojunction intercalation performance.The improvement in device performance is mainly due to the high short-circuit current,which is attributed to the enhanced carrier mobility and reduced bimolecular complexation.In conclusion,low-temperature continuous deposition of PM6Y6 constructs inverse pseudo-planar heterojunction organic solar cells in a novel way.The effect of different thickness electrodes on the device performance was simulated by optical simulation to determine the thickness of the device electrodes.Pseudo-planar heterojunction and bulk heterojunction transparent devices with 85 nm thickness were simulated,and the simulation results showed that the gradient distribution of donor and acceptor was favorable for exciton generation,while the normalized electric field intensity analysis showed that the pseudo-planar heterojunction devices had better visible light transmission rate.Based on the optical simulations,a series of inverse pseudo-planar heterojunction devices were constructed.The fabricated pseudo-planar heterojunction devices provide Power Conversion Efficiency(PCE)of 12.36%,23.19%of average visible transmittance(AVT)at 45:40 nm(D:A),while the bulk heterojunction devices obtain 10.82%PCE(20.73%AVT)at 85 nm(D:A=1:1.2).In addition,the pseudo-planar heterojunction devices exhibit better stability.In this thesis,an inverse pseudo-planar heterojunction transparent organic solar cell was constructed by low-temperature continuous deposition,and a double enhancement of PCE and AVT was obtained,which is of great value for the study of transparent organic solar cells and the preparation of pseudo-planar heterojunction by continuous deposition.