Research On The Improvement Of Perovskite Solar Cell Performance By Glucose

Glucose is a non-toxic,easily available and biocompatible material with multi-hydroxyl and aldehyde groups which has been intensively studied in the field of biology.According to pervious researches,carbonyl and hydroxyl groups has stong interaction with perovskite components for fabilicating highly performance and stabilized perovskite solar cells.However,the effect of molecules with multiple functional groups on perovskite solar cells is rarely investigated.Glucose with stabilized structure and it exists large quantities in nature and easy to prepare.Moreover,glucose has been widely studied in biology and photo-detector fileds.Therefore,it is of positive significance to extend the research of glucose in photovoltaic fields to fabricate highly performance and stabilized perovskite solar cells.In this paper,at first,we introduced glucose into the perovskite active layer to improve the performance and stability（light,heat,moisture）of inverted planar perovskite solar cells.Then according to the positive influence of glucose for active layer,we used glucose as an interlayer to modified the hole transport layer（P3CT-K）to optimize the properties of interface between P3CT-K and perovskite,all of which also improved the performance and film stability of inverted planar perovskite solar cells.The details research as following:（1）As conventional method to parpared the precursor solution,under 60℃ heating condition,we mixed glucose,MAI and PbI₂ into DMSO and DMF（1:4）to fabricate perovskite precursor solution.We used top-view SEM to explore the influence of glucose on the grain size of perovskite thin films.As the result,the modification of active layer by glucose is benefical to increase the grain size to obtain high quality perovskite films.The interaction betwwen glucose and perovskite components and the effect on crystallinity of perovskite film were measured by XPS,FTIR and XRD,which indicates that the interaction between glucose and perovskite components increase the crystallization of the perovskite film and has potential value for fabricate high quality perovskite film.Then the J-V curves,EQE,steady-state photocurrent and power output were measured to explore the influence of glucose on inverted planar perovskite solar cells performance.The results demonstrated that due to the glucose modification,the performance of inverted planar perovskite solar cells increased significantly.And the effect of glucose on devices trap states were measured by dark J-V curves,PL,TRPL,SCLC and EIS.The results of researches show that the defects in perovskite film were greatly passivated by glucose,leading to a higher V_oc,J_sc and FF.More importantly,we examined the environmental stability of the non-encapsulation devices by subjecting them to three important stress conditions:（1）heat,（2）light and（3）moisture.The results show that the stability of the MAPbI₃（glucose）devices was significantly improved,benefiting from the enhanced quality of the perovskite film with reduced grain boundaries and trap densities.In summary,the modification of the perovskite active layer by glucose improved the performance and stability of the device,explanes the research application of glucose on photovoltaic field,and provides a new strategy for the fabrication high performance inverted planar perovskite solar cells.（2）Base on the above research,glucose has positive effects on inverted planar perovskite solar cells,so,we fabricate the glucose interlayer between P3CT-K and perovskite active layer to explore the effect of perovskite performance.At first,we investigate the influence of glucose on hole transport layer by testing ITO/P3CT-K substrate transmittance,hole transmission rate,AFM and CA.The results showed that by modifiying P3CT-K with glucose interlayer,the transmission of the substrate was almost unchanged;the hole transmission rate was slightly improved;the interface roughness was decreased;and the permeability of the precursor solution to the HTL was increased,all of which provided condition for the fabrication of high-quality perovskite thin film with large grains and less grain boundaries.Used XPS and XRD to demonstrated that the C=O group of glucose has interaction with PbI₂ and increased the crystallization of perovskite film.The absorption strength increase of perovskite film was measured by UV-vis spectra,which is proved powerful evidence for increasing J_sc and FF of devices.The SEM results indicated that the glucose interlayer has benefical to increase grain size and improved film quality.According to the tests results of J-V cures,EQE et.al indicated that the invented planar perovskite solar cell with over20%PCE and negligible hysteresis effect was fabricated by modifying the device with glucose interlayer.Dark-current,PL,TRPL,EIS et.al tests have proved that the modification of the glucose interlayer reduces the trap states of PSCs,providing a reliable basis for explaining the improvement of device performance.Finally,perovskite films were heated continuously on a platform at 85℃,and the XRD of the films proved that the glucose interlayer was helpful to improve the thermal stability of the films with inhibit the degradation of MAPbI₃.This method provides an effective strategy for fabricating high performance inverted planar perovsite solar cells.By modifying the active layer and hole transport layer of perovskite solar cells with multifunctional glucose molecules,an effective stategy is provided fabrication of efficient and stable inverted planar perovskite solar cells.