Application Of LDHs Calcined Products In PbS QDs@Perovskite Hybrid Solar Cells

Perovskite solar cells is a photoelectric device with full potential,the power conversion efficiency(PCE)reaching a certified value of 25.5%in the last few years.The development of high-performance perovskite thin films is essential to further promote the efficiency of perovskite solar cells to a higher level.Those are common research techniques include solvent engineering,combination engineering,and interface engineering.Quantum dots are also a photovoltaic material with excellent performance.They have many advantages,such as high absorption coefficient,tunable band gap by controlling the diameter of nanoparticles,low cost,and solution processing.The introduction of quantum dots into perovskite materials can be used as an effective means to improve the quality of the perovskite layer.The hybridization of the two semiconductor materials also provides a new idea for the development of third-generation solar cells.At the same time,ZrO2 can improve the PCE of the solar cell which as a commonly used barrier material for perovskite solar cell.However,there are disadvantages such as high cost and difficulty in preparation.It is imperative to develop a low-cost and simple preparation method,which is prepared from layered double metal hydroxides(LDHs)precursors into mixed metal oxides(MMO)is such a preparation method.Therefore,this article focuses on the PbS QDs@perovskite hybrid system to study the absorption layer film and battery performance,and uses a carbon electrode system without a hole transport layer to develop a high performance,excellent stability and low cost.Solar battery.The specific operations are as follows:1.Based on pure MAPbI3 material,a carbon electrode system hole-transport-layer-free perovskite solar cell was prepared by a commercial carbon paste knife coating method.The structure of the constructed device is:FTO/cp-TiO2/mp-TiO2/MAPbI3/C.The performance of the devices prepared by the one-step method under different concentrations of precursors(1.2 M,1.3 M,1.4 M,1.5 M,1.6M)was compared.In the end,the performance of the device was the best at 1.5 M,obtaining 10.3%PCE,where Jsc=23.9 mA·cm-2,Voc=0.88 V,FF=0.49.In addition,Au electrodes with a thickness similar to that of the carbon electrodes and different hole transport layers were prepared,but the overall performance of the Au-PSC device was much lower than that of the C-PSC device,which proved the hole extraction ability of the C electrode.Moreover,the contribution of carbon electrodes to the stability of the device is also very large.After 480h plastic bag sealed storage,there is still 83%of the initial PCE,while this data of Au-PSC is only 51%.It is worth noting that the price of the carbon paste material is much lower than the Au electrode system,which can greatly reduce the cost.2.Synthesize a high-performance perovskite-quantum dot(QDs)hybrid film,and add PbS QDs to the CH3NH3PbI3(MAPbI3)precursor to form a QD-in-perovskite structure,which is conducive to the crystallization of perovskite.The grain size increases,the grain breakage decreases,the carrier separation efficiency increases,the XRD characteristic peak intensity increases,and the(220)plane in the XRD pattern accounts for a larger proportion.Taking advantage of these advantages,when adding 5%molar ratio of PbS QDs,the power conversion efficiency of PSC based on PbS@MAPbI3 hybridization is 24%higher than that of PSC based on pure perovskite,mainly due to higher current density Jsc And the fill factor FF.In the end,the PSC based on the hybrid film and the carbon electrode system can achieve an efficiency of 12.16%and an FF of 0.55 or more,and the wet stability is also improved compared to the Au electrode system.3.The Zr-O/ZnAl-LDH precursors of different proportions were synthesized in one step by the co-precipitation method,and then pyrolyzed at high temperature to prepare ZnAlZr MMO,which was applied to the mesoporous layer of PSC instead of the TiO2 mesoporous layer.This MMO contains ZnO(Al)and ZrO2(Al)crystals with good crystallinity,and has a good mesoporous structure.Utilizing the electron transport capacity of ZnO and the insulating properties of ZrO2,a three-level TiO2-ZnO-ZrO2 electron transport system is formed.Finally,when 4:1:2 ZnAlZr MMO is used as a mesoporous material,the best device performance is obtained.PCE is 9.92%,Jsc=23.9 mA·cm-2,Voc=0.90,FF=0.475,which is close to TiO2 device,which proves that ZnAlZr MMO It can be used as a feasible mesoporous material.In addition,based on the structural memory effect of LDH,this device also performs well in terms of stability.