摘要
基于透明聚合物基材的钙钛矿太阳电池(perovskite solar cell,PSC)具有高效、柔性、轻质、易集成于弯曲表面及可通过卷对卷技术来实现批量生产等优势,已成为太阳电池行业最具颠覆性的竞争者之一.然而,常用透明聚合物基材的玻璃转变温度较低,使得在刚性玻璃基材PSC开发中常用的、需要较高工艺温度的铟锡氧化物和掺氟氧化锡等透明电极及电子传输层材料,在透明聚合物基材上的高质量制备遇到了困难,这已成为限制基于聚合物基材的柔性PSC性能提升的主要瓶颈之一.本文采用射频磁控溅射技术在聚对苯二甲酸乙二醇酯(polyethylene terephthalate,PET)衬底上室温沉积了(aluminum-doped ZnO,AZO)/Ag/AZO多层结构无铟透明导电薄膜(transparent conductive film,TCF),研究了中间Ag层厚度对所沉积多层TCF光电特性的影响,并利用其作为透明电极,以低温溶液法制备的SnO2层作为电子传输层,进行了正置结构柔性PSC制备.研究发现,随着中间Ag层厚度的增加,样品的平均光透过率先增加后降低,而表面电阻则呈现单调减小的趋势.当Ag层厚度为11 nm时,多层TCF的品质因子最高,其值可达2.3×10–2Ω–1,此样品在400~800 nm波长范围内平均光透过率为83.3%,表面电阻为7.0Ω/sq.在PET衬底上制备的AZO/Ag/AZO/SnO2/Cs0.1(MA0.17FA0.83)0.9Pb(I0.83Br0.17)3/spiro-OMeTAD/MoO3/Ag柔性PSC的功率转换效率(power conversion efficiency,PCE)可达11.9%,并且在10 mm弯曲半径下弯折100次后,仍可保持其初始PCE的95%.
Perovskite solar cells(PSCs)fabricated on transparent polymer substrates are considered to be one of the most disruptive competitors in the solar cell industry for their favorable traits,including high efficiency,flexibility,light weight,portability,and compatibility with curved surfaces.More importantly,PSCs based on transparent polymer substrates could dramatically lower down the processing cost,by introducing high-throughput roll-to-roll manufacturing and lowtemperature energy-saving technological processes.However,due to the low glass transition temperatures of common transparent polymer substrates,it is difficult to prepare the traditional transparent electrodes such as indium tin oxide(ITO)and fluorine doped Sn O2(FTO)and the electron transport layer with efficient charge transport to meet the specifications of flexible PSCs as on rigid glass substrate,which has become a major bottleneck to improve the device performance of flexible PSCs based on transparent polymer substrates.In this paper,multilayer films of AZO/Ag/AZO are deposited onto heat-sensitive polyethylene terephthalate(PET)substrate by radio frequency magnetron sputtering technique at room temperature to develop indium-free flexible transparent conductive films(TCFs),which are utilized as transparent electrode to prepare flexible PSCs with planar regular structure.The effects of Ag mid-layer thickness on microstructure and photoelectric properties of the AZO/Ag/AZO multilayer films are investigated by scanning electron microscopy,UVVIS transmission spectra and four-point probe resistance measurements.It is found that when Ag layer thickness is less than 5 nm,Ag layer has the island structure and the electrical connection is very poor,so that the samples have a higher sheet resistance.As the thickness of Ag layer is increased,the Ag layer changes gradually from discontinuous structure to continuous structure,the sheet resistances of the samples decrease drastically.However,when the thickness of Ag layer is beyond 9 nm,the sheet resistances of the samples decrease slowly with further increasing the thickness of Ag layer.The analysis of optical transmission spectra indicates that with increasing the Ag layer thickness,the average transmittance in the visible light range of the AZO/Ag/AZO multilayer films increases first and then decreases.The Haacke figure of merit has been calculated for the AZO/Ag/AZO multilayer films.The best Haacke figure of merit of 2.3×10–2Ω–1 is obtained for the 11-nm-thick Ag mid-layer sample,which has an average transmittance of 83.3%in the spectral range of 400–800 nm and a sheet resistance of 7.0Ω/sq.In addition,the bending test indicates that the developed AZO/Ag/AZO multilayer TCFs also have excellent mechanical flexibility,and the relative change rate of sheet resistance is less than 8%after 1000 bending cycles with a 5-mm bending radius.The flexible PSCs are fabricated with a configuration of Ag/Mo O3/spiro-OMe TAD/perovskite/Sn O2/AZO/Ag/AZO on PET substrates.The mixed cation and mixed halide perovskite films are prepared by a single step inverse solvent crystallization method.Considering that Sn O2 layer presents advantages of low-temperature processability and modulating the band level mismatch at the interface between the AZO/Ag/AZO and the perovskite layer,Sn O2 electron transport layer is fabricated by spin-coating the aqueous soluble Sn O2 nanoparticles and annealing at a low temperature of 120°C.The flexible PSC based on the optimized AZO/Ag/AZO transparent electrode achieves power conversion efficiency(PCE)of 11.9%.At a bending radius of 10 mm,flexible PSC based on AZO/Ag/AZO multilayer electrodes maintains 95%of their initial PCE even after 100 bending cycles.
作者
蒋树刚
路万兵
汪鑫
刘红燕
张文修
刘海旭
于威
Shugang Jiang;Wanbing Lu;Xin Wang;Hongyan Liu;Wenxiu Zhang;Haixu Liu;Wei Yu(Hebei Key Laboratory of Optic-Electronic Information and Materials,College of Physics Science and Technology,Hebei University,Baoding 071002,China;College of Automotive and Electronic Engineering,Baoding University,Baoding 071002,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2020年第32期3602-3609,共8页
Chinese Science Bulletin
基金
国家重点研发计划(2018YFB1500503)
河北省自然科学基金(F2017201101)资助。
关键词
柔性钙钛矿太阳电池
多层透明电极
氧化锡
聚合物衬底
无铟
flexible perovskite solar cell
multilayer transparent electrode
tin oxide
polymer substrate
indium-free
