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基于n-MAGeI3/p-MAGeI3同质结的高效钙钛矿太阳能电池模拟研究

赵贺彤, 王世茂, 武豪, 侯显

赵贺彤, 王世茂, 武豪, 等. 基于n-MAGeI3/p-MAGeI3同质结的高效钙钛矿太阳能电池模拟研究[J]. 复合材料学报, 2024, 43(0): 1-8.
引用本文: 赵贺彤, 王世茂, 武豪, 等. 基于n-MAGeI3/p-MAGeI3同质结的高效钙钛矿太阳能电池模拟研究[J]. 复合材料学报, 2024, 43(0): 1-8.
ZHAO Hetong, WANG Shimao, WU Hao, et al. Simulation research of high efficiency perovskite solar cells based on n-MAGeI3/p-MAGeI3 homojunction[J]. Acta Materiae Compositae Sinica.
Citation: ZHAO Hetong, WANG Shimao, WU Hao, et al. Simulation research of high efficiency perovskite solar cells based on n-MAGeI3/p-MAGeI3 homojunction[J]. Acta Materiae Compositae Sinica.

基于n-MAGeI3/p-MAGeI3同质结的高效钙钛矿太阳能电池模拟研究

基金项目: 兰州理工大学红柳优秀青年人才支持项目(062210);兰州理工大学博士科研启动基金(061806);国家自然科学基金地区科学基金项目(52462033)
详细信息
    通讯作者:

    侯显,博士,副教授,硕士生导师,研究方向为高性能、大面积钙钛矿太阳能电池材料与器件研究 E-mail: houx@lut.edu.cn

  • 中图分类号: TM914.4;TB333

Simulation research of high efficiency perovskite solar cells based on n-MAGeI3/p-MAGeI3 homojunction

Funds: Hongliu Distinguished Young Talent Support Program Project of Lanzhou University of Technology (062210); Doctoral Scientific Research Foundation of Lanzhou University of Technology (061806); Regional Project of National Natural Science Foundation of China(52462033)
  • 摘要: 在保证光电转换效率和稳定性的前提下,减少或替代铅的使用是钙钛矿太阳能电池(PSCs)绿色发展的重要任务。本文了设计了一种以n-MAGeI3/p-MAGeI3锗基钙钛矿同质结为光吸收层,Cd0.5Zn0.5S和MASnBr3分别为电子传输层(ETL)和空穴传输层(HTL)结构的钙钛矿太阳能电池。采用SCAPS-1D 软件模拟研究了该器件的光电性能,发现n-MAGeI3/p-MAGeI3同质结钙钛矿光吸收层的光生载流子解离性能优于单层MAGeI3钙钛矿的。Cd0.5Zn0.5S 作为ETL比传统TiO2有更加匹配的能级位置, MASnBr3作为HTL不仅可以起到空穴传输作用,还可以补充吸收钙钛矿层未吸收完的光子进而产生电子空穴对,从而提升电池的光电性能。对器件结构与缺陷密度进行优化后,得到 VOC = 1.9069 V, JSC = 15.1388 mA/cm2, FF = 88.69%, PCE=25.60%的光电性能,优于对比器件TiO2/MAGeI3/Spiro-OMeTAD 23.47%的PCE和Cd0.5Zn0.5S/MAGeI3/MASnBr3器件25.33%的PCE

     

    Abstract: It is an important task for the future green development of perovskite solar cells (PSCs) to reducing or replacing the use of lead (Pb) with the premise of ensuring the power conversion efficiency (PCE) and stability. Herein, a PSCs hired a germanium-based n-MAGeI3/p-MAGeI3 perovskite homojunction as light absorbing layer, Cd0.5Zn0.5S as electron transport layer (ETL) and MASnBr3 as hole transport layer (HTL) was designed. SCAPS-1D software was used to simulate the photoelectric performance of the device. It was found that the n-MAGeI3/p-MAGeI3 homojunction structure show a superior photo-carriers dissociation and transportation than the single MAGeI3 absorb layer. The use of Cd0.5Zn0.5S as an ETL has a more matched energy level position than traditional TiO2 ETL. The MASnBr3 HTL can realize the dual functions of hole transportation and supplement absorb the unabsorbed photons of the perovskite layer to generate electron-hole pairs, and thus improving the device performance. After optimization of the device structure and defect density of perovskite layer, we got a high-performance germanium-based PSCs with a VOC of 1.9069 V, JSC of 15.1388 mA/cm2, FF of 88.69% and PCE of 25.60%. While the control device with the TiO2/MAGeI3/Spiro-OMeTAD structure only show a PCE of 23.47% , and the Cd0.5Zn0.5S/MAGeI3/MASnBr3 device show a PCE of 25.33%.

     

  • 钙钛矿太阳能电池(PSCs)的光电转换效率(PCE)已经超过26%[1],是当前光伏领域的研究热点。然而,目前已得到的高效PSCs 大多基于MAPbI3、FAPbI3、CsPbI3等含铅钙钛矿。最近的研究表明,以MAPbI3、FAPbI3、MA0.1FA0.9Pb0.85Sr0.15I3分别作为吸收层,其模拟光电转换效率最高可达25.20%[2]、27.49%[3]、29%[4],虽然已经取得较高的PCE,但其光吸收层均含Pb2+,这与太阳能电池的绿色发展理念不符[5]。因此,研究无铅高效钙钛矿光吸收材料也是当前PSCs研究的一个重要方向。

    为了改善无铅或少铅钙钛矿中载流子的输运特性,通过匹配两种或多种无铅(少铅)钙钛矿形成异质结或同质结,从而提升PSCs的光电转换效率。如构建的无铅异质结钙钛矿(FASnI3/CsSnI3)光吸收层表现出更好的光吸收能力,且异质结的内建电场[6]促进了光诱导电荷的定向运动,降低了载流子复合损失,从而提升器件的PCE[7]

    此外,电子传输材料与空穴传输材料的特性对PSCs的性能也有非常大的影响。常用的TiO2由于需要高温退火处理以及其较强的光催化性能,不是理想的电子传输材料。而经典的Spiro-OMeTAD空穴传输材料由于造价昂贵、需要添加剂、稳定性差等问题,也一直困扰着PSCs的发展[8-10]。因此,寻求新的电子/空穴传输材料显得尤为重要。考虑到载流子的高效解离与输运,对电子传输材料来说,应选择导带底(CB)水平且迁移率较高的材料。而对于空穴传输材料来说,由于其价带顶(VB)一般高于钙钛矿,在钙钛矿/HTL界面形成较大能带差,不利于载流子输运导致电池性能下降。对此,应选择VB低于钙钛矿的空穴传输材料[11]

    针对上述考虑,本文设计了一种以n-MAGeI3/p-MAGeI3锗基钙钛矿同质结为光吸收层的PSCs。运用SCAPS-1D 软件对比研究了不同材料作为ETL和HTL对钙钛矿太阳能电池器件性能的影响。对n-MAGeI3/p-MAGeI3同质结光吸收层中的缺陷密度及载流子行为进行了优化,并对MASnBr3基HTL的光吸收和空穴传输的双重功能进行了分析论证。

    SCAPS-1D软件通过解析静电势能与电荷分布的内在联系,精确描绘了太阳能电池内部复杂的光电转换机制,包括载流子运动、缺陷交互及其对电池性能的综合影响[12]

    在该软件中,太阳能电池的性能是通过求解泊松方程、电子连续性方程和空穴连续性方程来实现的,具体方程如下。

    泊松方程:

    x(ε(x)Vx)=q[p(x)n(x)+N+D(x)NA(x)+pt(x)nt(x)] (1)

    空穴连续性方程:

    pt=1qJpx+GpRp (2)

    电子连续性方程:

    nt=1qJnx+GnRn (3)

    其中q是电荷,ε是介电常数,V是电势,p(x)是自由空穴浓度,n(x)是自由电子浓度,ND+ (x)是电离供体浓度,NA+(x)是电离受体浓度,pt(x)是空穴阱密度,nt(x)是电子阱密度,Jn是电子的电流密度,Jp是空穴的电流密度,Gn是电子产生率,Gp为空穴生成率,Rn为电子的复合速率,Rp为空穴的复合速率。

    为了说明不同的ETL与HTL材料对器件产生的影响,对照器件的ETL与HTL分别选用常用的TiO2与Spiro-OMeTAD;实验器件以Cd0.5Zn0.5S为ETL,MASnBr3为HTL。

    以MAGeI3锗基钙钛矿光吸收层为对照器件,以n-MAGeI3/p-MAGeI3同质结构的锗基钙钛矿光吸收层为实验器件,具体参数如表1表2所示。

    表  1  用于模拟钙钛矿太阳能电池(PSC)性能的实验材料参数
    Table  1.  Enter the experimental material parameters used to simulate perovskite solar cell (PSC) properties
    Cd0.5Zn0.5S
    (ETL)
    n-MAGeI3 p-MAGeI3 MASnBr3
    (HTL)
    Eg/eV 2.8 1.9 1.9 2.15
    χ/eV 3.8 3.98 3.98 3.39
    εr 10 10 10 8.2
    NC/cm−3 1018 1016 1016 1018
    NV/cm−3 1018 1015 1015 1018
    μn/(cm2·V−1·s−1) 100 162 162 1.6
    μp/(cm2·V−1·s−1) 25 101 101 1.6
    ND/cm−3 1017 1015 0 0
    NA/cm−3 0 0 1017 1018
    Nt/cm−3 1014 1014 1014 1014
    Thickness/nm 200 480 60 200
    References [11] [14] [14] [11]
    Notes:Eg is the bandgap; χ is the electron affinity; εr is the dielectric permittivity; NC is the CB effective density of states; NV is the VB effective density of states; μn is the electron mobility; μp is the hole mobility; ND is the shallow uniform donor density; NA is the shallow uniform acceptor density; Nt is the total density.
    下载: 导出CSV 
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    表  2  用于模拟PSC性能的对照材料参数
    Table  2.  Enter control material parameters to simulate PSC performance
    TiO2
    (ETL)
    MAGeI3 Spiro-OMeTAD
    (HTL)
    FTO
    Eg/eV 3.2 1.9 3 3.5
    χ/eV 4 3.98 2.45 4
    εr 19 10 3 9
    NC/cm−3 2×1018 1016 2.2×1018 2.2×1018
    NV/cm−3 2×1019 1016 1.9×1019 1.8×1019
    μn/(cm2·V−1·s−1) 0.2 1.62×105 2×10−4 20
    μp/(cm2·V−1·s−1) 0.1 1.01×105 2×10−4 10
    ND/cm−3 3×1019 109 0 1019
    NA/cm−3 0 109 1018 0
    Nt/cm−3 1014 1014 1014 1014
    Thickness/nm 200 540 200 50
    References [14] [15] [14] [16]
    下载: 导出CSV 
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    以金属Pt为背电极,其功函数为5.7 eV[13]

    对ETL和HTL层厚度进行优化,并对p-n同质结中p型与n型钙钛矿吸收层缺陷密度分别进行优化,对比分析不同缺陷密度下对器件性能的影响

    采用表1表2中所列出的ETL、吸光层及HTL材料分别组装了FTO/TiO2/MAGeI3/Spiro-OMeTAD/Pt、FTO/Cd0.5Zn0.5S/MAGeI3/MASnBr3/Pt和FTO/Cd0.5Zn0.5S/n-MAGeI3/p-MAGeI3/MASnBr3/Pt结构的器件,模拟器件在AM 1.5 G光照条件下的光电性能,得到如图1(a)所示的J-V曲线。TiO2/MAGeI3/Spiro-OMeTAD结构的器件得到23.63%的PCE,而Cd0.5Zn0.5S与MASnBr3分别作为ETL与HTL的器件中,以单层MAGeI3为光吸收层的器件表现出25.07%的PCE[17],以n-MAGeI3/p-MAGeI3同质结作为吸光层的器件PCE提升至25.34%,具体参数见表1图1(b)为三种器件对应的QE曲线。基于Cd0.5Zn0.5S与MASnBr3传输层的器件QE峰值均接近100%,而FTO/TiO2/MAGeI3/Spiro-OMeTAD/Pt器件的QE值明显较低,究其原因,可能与MASnBr3作为光吸收层增加光吸收有关,也有可能与n-MAGeI3/p-MAGeI3同质结利于光生载流子传输有关[18-19]

    图  1  电子传输层(ETL)与空穴传输层(HTL)的厚度均为200 nm时三种器件对应的(a) J-V曲线;(b) QE曲线
    Figure  1.  (a) J-V curves corresponding to the three devices when the thickness of electron transport layer (ETL) and hole transport layer (HTL) are both 200 nm; (b) The QE curve

    图2(a)所示的AM 1.5 G光谱经FTO、Cd0.5Zn0.5S、n-MAGeI3/p-MAGeI3依次吸收后,剩余光谱如图2(b)所示,在520-800 nm之间还有部分光未被吸收。而MASnBr3的禁带宽度(Eg)为2.15 eV[11],恰好可吸收520-577 nm的的太阳光谱。此外,MASnBr3的价带(VB)能级低于MAGeI3钙钛矿[11,20],可在钙钛矿/MASnBr3界面处可形成能量尖峰,使得载流子复合的活化能较高,更利于空穴传输,从而提高电池的光电转换效率[21]。对此,MASnBr3可实现有效吸收光子和促进空穴传输的双重功能[22]

    图  2  (a) AM 1.5 G标准光谱;(b) 经过吸收层后的光谱
    Figure  2.  (a) AM 1.5 G standard spectrum; (b) Spectrum after the absorption layer
    表  3  三种器件的光伏参数
    Table  3.  Photovoltaic parameters of three kinds of devices
    VOC/
    V
    JSC/
    (mA·cm−2)
    FF/
    %
    PCE/
    %
    TiO2/MAGeI3/Spiro-OMeTAD1.852914.706986.7323.63
    Cd0.5Zn0.5S/MAGeI3/MASnBr31.853114.988890.2525.07
    Cd0.5Zn0.5S/n-MAGeI3/
    p-MAGeI3/MASnBr3
    1.906614.986788.6925.34
    Notes:VOC is the open-circuit voltage; JSC is the short-circuit current; FF is the filling factor; PCE is the photoelectric conversion efficiency.
    下载: 导出CSV 
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    图3为各器件的能带结构示意图。Vbi是由钙钛矿材料的导带最小值与电子的价带最大值之间的能级差决定的,而VOCVbi之间存在重要关系,Vbi越高则VOC越高[15]。MAGeI3对于HTL(Cd0.5Zn0.5S)来说具有更加匹配的能级,作为中间层可以调节势垒高度。TiO2/MAGeI3/Spiro-OMeTAD器件的Vbi为1.366 eV,与其他钙钛矿光吸收层相比显示出较低的Vbi[23]。而n-MAGeI3和p-MAGeI3形成的pn结产生的内建电场增大了势垒高度。因此,在Cd0.5Zn0.5S/MAGeI3/MASnBr3和Cd0.5Zn0.5S/n-MAGeI3/p-MAGeI3/MASnBr3的情况下,Vbi有所增加,分别达到1.547 V和1.591 V。

    图  3  三种器件结构所对应的能带图(a) TiO2/MAGeI3/Spiro-OMeTAD结构;(b) Cd0.5Zn0.5S/MAGeI3/MASnBr3结构;(c) Cd0.5Zn0.5S/n-MAGeI3/p-MAGeI3/MASnBr3结构
    Figure  3.  The energy band diagram corresponding to the three device structures (a) TiO2/MAGeI3/Spiro-OMeTAD structures; (b) Cd0.5Zn0.5S/MAGeI3/MASnBr3 structures; (c) Cd0.5Zn0.5S/n-MAGeI3/p-MAGeI3/MASnBr3 structure

    综上所述,Cd0.5Zn0.5S/MAGeI3/MASnBr3和Cd0.5Zn0.5S/n-MAGeI3/p-MAGeI3/MASnBr3结构相似,但由于n-MAGeI3和p-MAGeI3形成的pn结会产生内建电场,使得Cd0.5Zn0.5S/n-MAGeI3/p-MAGeI3/MASnBr3结构具有较高的Vbi,从而使器件表现出较好的光伏性能。

    在Cd0.5Zn0.5S/n-MAGeI3/p-MAGeI3/MASnBr3器件中,研究ETL与HTL的厚度对器件性能的影响,结果如图4所示。在选定HTL厚度为200 nm,改变ETL厚度时,发现ETL厚度对器件性能影响不大。在选定ETL厚度为200 nm的情况下,通过Lambert-Beer定律(如下式)[24]计算透过后光的强度。

    图  4  不同 ETL厚度下(a) J-V曲线;(b) QE曲线;不同HTL厚度下(c) J-V曲线;(d) QE曲线
    Figure  4.  (a) J-V curve under different ETL thicknesses; (b) QE curve; (c) J-V curves under different HTL thicknesses; (d) QE curve
    S(λ)=S0(λ)exp(4i=1amati(λ)dmati) (4)

    式中S0(λ)为AM 1.5 G入射光的强度,S(λ)为透过光的强度,amati为材料的吸收系数,dmati为给定器件层的厚度。计算可得,当HTL为500 nm时,器件可将剩余520 nm-577 nm的光吸收完全,此时器件性能可从25.17%提升至25.60%,所以HTL的最佳厚度应为500 nm。详细参数见表1表2

    上述研究表明,在该器件中,HTL厚度对器件的性能影响大于ETL,且ETL与HTL最佳厚度应分别为100 nm与500 nm。

    表  4  HTL厚度200 nm下对Cd0.5Zn0.5S(ETL) 厚度优化
    Table  4.  Optimization of Cd0.5Zn0.5S(ETL) thickness at 200 nm HTL thickness
    Thickness/nmVOC/VJSC/(mA·cm−2)FF/%PCE/%
    501.906414.984288.6925.33
    1001.906514.985388.6925.34
    2001.906614.986788.6925.34
    3001.906614.987188.6925.34
    4001.906614.986788.6925.34
    5001.906514.985488.6925.34
    下载: 导出CSV 
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    表  5  ETL厚度200 nm下对MASnBr3(HTL) 厚度优化
    Table  5.  Optimization of MASnBr3(HTL) thickness at 200 nm ETL thickness
    Thickness/nmVOC/VJSC/(mA·cm−2)FF/%PCE/%
    501.906214.822288.6925.06
    1001.906314.887888.6925.17
    2001.906614.986788.6925.34
    3001.906715.055388.6925.46
    4001.906815.103888.6925.54
    5001.906915.138888.6925.60
    下载: 导出CSV 
    | 显示表格

    图5给出了n-typeMAGeI3与p-typeMAGeI3层不同的缺陷密度对器件性能的影响。图5(a)描述了在保持p型MAGeI3 层缺陷密度为1014 cm−3。不变的情况下,器件光伏参数随n-MAGeI3缺陷密度的变化情况。当n-MAGeI3缺陷密度从1018 cm−3下降到1010 cm−3时,JSC从14.80 mA/cm2 提升到15.14 mA/cm2VOC从1.51 V提升到了1.96 V,FF从72.89%提升到了91.58%,PCE从16.30%提升到了27.15%。图5(b)描述了在保持n-MAGeI3层缺陷密度为1014 cm−3不变的情况下,器件光伏参数随p-MAGeI3缺陷密度的变化,当p-MAGeI3缺陷密度从1018 cm−3下降到1010 cm−3时,PCE从20.69%提升到了25.66%,发现p-MAGeI3层缺陷密度对器件性能的影响小于n-MAGeI3层。其原因主要是由于太阳光通过FTO玻璃一侧照射,光生载流子的数量在n-MAGeI3层比在p-MAGeI3层多[14]。由于n-MAGeI3层参与复合的载流子数量高于p-MAGeI3层,这意味着在n-MAGeI3层中,有更多的载流子在传输过程中可能发生复合。因此,n-MAGeI3层的厚度[25]对其载流子传输效率具有重要影响。过厚的n-MAGeI3层也意味着载流子需要传输更长的距离才能到达ETL或被收集。这可能会增加载流子在传输过程中的复合率和能量损失。从而导致n-MAGeI3层缺陷密度对器件性能的影响大于p-MAGeI3层。

    图  5  (a) 在p-type MAGeI3层缺陷密度为1014 cm−3时n-typeMAGeI3缺陷密度对性能的影响;(b) 在n-type MAGeI3层缺陷密度为1014 cm−3时p-typeMAGeI3缺陷密度对性能的影响
    Figure  5.  (a) Effect of n-typeMAGeI3 defect density on performance when p-type MAGeI3 layer defect density is 1014 cm−3; (b) Influence of p-typeMAGeI3 defect density on performance when n-type MAGeI3 layer defect density is 1014 cm−3

    由此可见,FTO/Cd0.5Zn0.5S/n-MAGeI3/p-MAGeI3/MASnBr3/Pt器件中,n-typeMAGeI3与p-typeMAGeI3层掺杂的缺陷密度接近实际情况时,即温度为300 K,Cd0.5Zn0.5S(ETL)厚度为100 nm,MASnBr3(HTL)厚度为500 nm,n-MAGeI3层与p-MAGeI3层缺陷密度均为1014 cm−3时,钙钛矿太阳能电池器件性能最佳:VOC = 1.9069 V, JSC = 15.1388 mA/cm2, FF = 88.69%, PCE = 25.60%。

    表  6  优化后的器件光伏参数
    Table  6.  The photovoltaic parameters of the device are optimized
    VOC/
    V
    JSC/
    (mA·cm−2)
    FF/
    %
    PCE/%
    TiO2/MAGeI3/
    Spiro-OMeTAD
    1.853014.726186.0123.47
    Cd0.5Zn0.5S/MAGeI3/
    MASnBr3
    1.853515.141890.2425.33
    Cd0.5Zn0.5S/n-MAGeI3/
    p-MAGeI3/MASnBr3
    1.906915.138888.6925.60
    下载: 导出CSV 
    | 显示表格
    图  6  优化厚度后三种器件结构对应的(a) J-V曲线;(b) QE曲线
    Figure  6.  (a) J-V curves corresponding to the three device structures after optimized thickness; (b) The QE curve

    本文主要通过SCAPS-1D软件模拟研究了无铅锗基钙钛矿太阳能电池的各项光伏参数,主要结论如下:

    (1)以Cd0.5Zn0.5S与MASnBr3材料分别作为器件的电子传输层(ETL)与空穴传输层(HTL),相比于普遍使用的TiO2与Spiro-OMeTAD,使得器件性能有了改善。

    (2)以MASnBr3作为HTL可实现有效吸收光子和促进空穴传输的双重功能。

    (3)采用n-MAGeI3/p-MAGeI3同质结作为钙钛矿光吸收层可以有效减少电子-空穴复合,其形成的pn结会产生内建电场,使载流子管理机制得到优化,从而改善电池性能。

    (4)通过对比n-MAGeI3与p-MAGeI3的缺陷浓度对器件性能的影响,发现n-MAGeI3的缺陷浓度对电池性能的影响大于p-MAGeI3缺陷浓度。在接近实际情况下,即当两者缺陷浓度均为1014 cm−3时,电池器件各项性能指标最佳,最终得到 Voc1.9069 V, Jsc15.1388 mA/cm2, FF为88.69%, PCE为25.60%的锗基钙钛矿太阳能电池器件。

  • 图  1   电子传输层(ETL)与空穴传输层(HTL)的厚度均为200 nm时三种器件对应的(a) J-V曲线;(b) QE曲线

    Figure  1.   (a) J-V curves corresponding to the three devices when the thickness of electron transport layer (ETL) and hole transport layer (HTL) are both 200 nm; (b) The QE curve

    图  2   (a) AM 1.5 G标准光谱;(b) 经过吸收层后的光谱

    Figure  2.   (a) AM 1.5 G standard spectrum; (b) Spectrum after the absorption layer

    图  3   三种器件结构所对应的能带图(a) TiO2/MAGeI3/Spiro-OMeTAD结构;(b) Cd0.5Zn0.5S/MAGeI3/MASnBr3结构;(c) Cd0.5Zn0.5S/n-MAGeI3/p-MAGeI3/MASnBr3结构

    Figure  3.   The energy band diagram corresponding to the three device structures (a) TiO2/MAGeI3/Spiro-OMeTAD structures; (b) Cd0.5Zn0.5S/MAGeI3/MASnBr3 structures; (c) Cd0.5Zn0.5S/n-MAGeI3/p-MAGeI3/MASnBr3 structure

    图  4   不同 ETL厚度下(a) J-V曲线;(b) QE曲线;不同HTL厚度下(c) J-V曲线;(d) QE曲线

    Figure  4.   (a) J-V curve under different ETL thicknesses; (b) QE curve; (c) J-V curves under different HTL thicknesses; (d) QE curve

    图  5   (a) 在p-type MAGeI3层缺陷密度为1014 cm−3时n-typeMAGeI3缺陷密度对性能的影响;(b) 在n-type MAGeI3层缺陷密度为1014 cm−3时p-typeMAGeI3缺陷密度对性能的影响

    Figure  5.   (a) Effect of n-typeMAGeI3 defect density on performance when p-type MAGeI3 layer defect density is 1014 cm−3; (b) Influence of p-typeMAGeI3 defect density on performance when n-type MAGeI3 layer defect density is 1014 cm−3

    图  6   优化厚度后三种器件结构对应的(a) J-V曲线;(b) QE曲线

    Figure  6.   (a) J-V curves corresponding to the three device structures after optimized thickness; (b) The QE curve

    表  1   用于模拟钙钛矿太阳能电池(PSC)性能的实验材料参数

    Table  1   Enter the experimental material parameters used to simulate perovskite solar cell (PSC) properties

    Cd0.5Zn0.5S
    (ETL)
    n-MAGeI3 p-MAGeI3 MASnBr3
    (HTL)
    Eg/eV 2.8 1.9 1.9 2.15
    χ/eV 3.8 3.98 3.98 3.39
    εr 10 10 10 8.2
    NC/cm−3 1018 1016 1016 1018
    NV/cm−3 1018 1015 1015 1018
    μn/(cm2·V−1·s−1) 100 162 162 1.6
    μp/(cm2·V−1·s−1) 25 101 101 1.6
    ND/cm−3 1017 1015 0 0
    NA/cm−3 0 0 1017 1018
    Nt/cm−3 1014 1014 1014 1014
    Thickness/nm 200 480 60 200
    References [11] [14] [14] [11]
    Notes:Eg is the bandgap; χ is the electron affinity; εr is the dielectric permittivity; NC is the CB effective density of states; NV is the VB effective density of states; μn is the electron mobility; μp is the hole mobility; ND is the shallow uniform donor density; NA is the shallow uniform acceptor density; Nt is the total density.
    下载: 导出CSV

    表  2   用于模拟PSC性能的对照材料参数

    Table  2   Enter control material parameters to simulate PSC performance

    TiO2
    (ETL)
    MAGeI3 Spiro-OMeTAD
    (HTL)
    FTO
    Eg/eV 3.2 1.9 3 3.5
    χ/eV 4 3.98 2.45 4
    εr 19 10 3 9
    NC/cm−3 2×1018 1016 2.2×1018 2.2×1018
    NV/cm−3 2×1019 1016 1.9×1019 1.8×1019
    μn/(cm2·V−1·s−1) 0.2 1.62×105 2×10−4 20
    μp/(cm2·V−1·s−1) 0.1 1.01×105 2×10−4 10
    ND/cm−3 3×1019 109 0 1019
    NA/cm−3 0 109 1018 0
    Nt/cm−3 1014 1014 1014 1014
    Thickness/nm 200 540 200 50
    References [14] [15] [14] [16]
    下载: 导出CSV

    表  3   三种器件的光伏参数

    Table  3   Photovoltaic parameters of three kinds of devices

    VOC/
    V
    JSC/
    (mA·cm−2)
    FF/
    %
    PCE/
    %
    TiO2/MAGeI3/Spiro-OMeTAD1.852914.706986.7323.63
    Cd0.5Zn0.5S/MAGeI3/MASnBr31.853114.988890.2525.07
    Cd0.5Zn0.5S/n-MAGeI3/
    p-MAGeI3/MASnBr3
    1.906614.986788.6925.34
    Notes:VOC is the open-circuit voltage; JSC is the short-circuit current; FF is the filling factor; PCE is the photoelectric conversion efficiency.
    下载: 导出CSV

    表  4   HTL厚度200 nm下对Cd0.5Zn0.5S(ETL) 厚度优化

    Table  4   Optimization of Cd0.5Zn0.5S(ETL) thickness at 200 nm HTL thickness

    Thickness/nmVOC/VJSC/(mA·cm−2)FF/%PCE/%
    501.906414.984288.6925.33
    1001.906514.985388.6925.34
    2001.906614.986788.6925.34
    3001.906614.987188.6925.34
    4001.906614.986788.6925.34
    5001.906514.985488.6925.34
    下载: 导出CSV

    表  5   ETL厚度200 nm下对MASnBr3(HTL) 厚度优化

    Table  5   Optimization of MASnBr3(HTL) thickness at 200 nm ETL thickness

    Thickness/nmVOC/VJSC/(mA·cm−2)FF/%PCE/%
    501.906214.822288.6925.06
    1001.906314.887888.6925.17
    2001.906614.986788.6925.34
    3001.906715.055388.6925.46
    4001.906815.103888.6925.54
    5001.906915.138888.6925.60
    下载: 导出CSV

    表  6   优化后的器件光伏参数

    Table  6   The photovoltaic parameters of the device are optimized

    VOC/
    V
    JSC/
    (mA·cm−2)
    FF/
    %
    PCE/%
    TiO2/MAGeI3/
    Spiro-OMeTAD
    1.853014.726186.0123.47
    Cd0.5Zn0.5S/MAGeI3/
    MASnBr3
    1.853515.141890.2425.33
    Cd0.5Zn0.5S/n-MAGeI3/
    p-MAGeI3/MASnBr3
    1.906915.138888.6925.60
    下载: 导出CSV
  • [1] 陆成伟, 欧阳雨洁, 张胜军, 等. 基于GO在Ge-基钙钛矿太阳能电池中的应用研究[J]. 价值工程, 2024, 43(1): 110-112. DOI: 10.3969/j.issn.1006-4311.2024.01.035

    LU Chengwei, OUYANG Yujie, HAO yanling, et al. Research on the Application of GO in Ge-based Perovskite Solar Cells[J]. Value Engineering, 2024, 43(1): 110-112(in Chinese). DOI: 10.3969/j.issn.1006-4311.2024.01.035

    [2] 肖建敏, 袁吉仁, 王鹏, 等. 铅基卤化物钙钛矿太阳电池的模拟研究[J]. 人工晶体学报, 2022, 51(6): 1051-1058. DOI: 10.3969/j.issn.1000-985X.2022.06.013

    XIAO Jianmin, YUAN Jiren, WANG Peng, et al. Simulation of Lead-Based Halide Perovskite Solar Cells[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2022, 51(6): 1051-1058(in Chinese). DOI: 10.3969/j.issn.1000-985X.2022.06.013

    [3]

    REKHA Rani, KAMIL Monga, SHILPI Chaudhary et al. Simulation of efficient Sn/Pb-based formamidinium perovskite solar cells with variation of electron transport layers[J]. Physica Scripta, 2023, 98 075910.

    [4]

    ABENA A M N, NGOUPO A T, NDJAKA J M B. Computational analysis of mixed cation mixed halide-based perovskite solar cell using SCAPS-1D software[J]. Heliyon, 2022, 8(11).

    [5]

    HAO L S, ZHOU M, SONG Y B, et al. Tin-based perovskite solar cells: Further improve the performance of the electron transport layer-free structure by device simulation[J]. Solar Energy, 2021, 230: 345-354. DOI: 10.1016/j.solener.2021.09.091

    [6]

    CHENG J, CAO H, ZHANG S, et al. Reinforcing built-in electric field to enable efficient carrier extraction for high-performance perovskite solar cells[J]. Materials Chemistry Frontiers, 2024, 8: 956-985. DOI: 10.1039/D3QM00956D

    [7]

    SAJID S, ALZAHMI S, SALEM I B, et al. Lead-Free Perovskite Homojunction-Based HTM-Free Perovskite Solar Cells: Theoretical and Experimental Viewpoints[J]. Nanomaterials, 2023, 13(6): 983. DOI: 10.3390/nano13060983

    [8]

    LIANG J, LIU J, JIN Z. All-inorganic halide perovskites for optoelectronics: progress and prospects[J]. Solar Rrl, 2017, 1(10): 1700086. DOI: 10.1002/solr.201700086

    [9]

    YANG T C J, FIALA P, JEANGROS Q, et al. High-bandgap perovskite materials for multijunction solar cells[J]. Joule, 2018, 2(8): 1421-1436. DOI: 10.1016/j.joule.2018.05.008

    [10]

    CHEN H N, XIANG S S, LI W, et al. Inorganic perovskite solar cells: a rapidly growing field[J]. Solar Rrl, 2018, 2(2): 1700188. DOI: 10.1002/solr.201700188

    [11]

    GAN Y J, BI X G, LIU Y C, et al. Numerical investigation energy conversion performance of tin-based perovskite solar cells using cell capacitance simulator[J]. Energies (Basel), 2020, 13: 5907. DOI: 10.3390/en13225907

    [12]

    PINDOLIA G, Shinde S M, JHA P K, et al. Optimization of an inorganic lead free RbGeI3 based perovskite solar cell by SCAPS-1D simulation. [J] Solar Energy 2022, 236: 802-821.

    [13]

    VINCENT M E N, SRINIVASAN D, MARASAMY L. Emerging BaZrS3 and Ba (Zr, Ti) S3 chalcogenide perovskite solar cells: A numerical approach toward device engineering and unlocking efficiency[J]. ACS omega, 2024, 9(4): 4359-4376. DOI: 10.1021/acsomega.3c06627

    [14]

    HIMA A, LAKHDAR N. Design and simulation of homojunction perovskite CH3NH3GeI3 solar cells[J]. Indian Journal of Physics, 2023, 97(3): 727-731. DOI: 10.1007/s12648-022-02419-8

    [15]

    SINGH N, AGARWAL A, AGARWAL M. Numerical simulation of highly efficient lead-free all-perovskite tandem solar cell[J]. Solar Energy, 2020, 208: 399-410. DOI: 10.1016/j.solener.2020.08.003

    [16]

    LI X K, LI J W, WU S K, et al. Theoretical analysis of all-inorganic solar cells based on numerical simulation of CsGeI3/CsPbI3 with pp+ built in electric field[J]. Solar Energy, 2022, 247: 315-329. DOI: 10.1016/j.solener.2022.10.039

    [17]

    MUSHTAQ S, TAHIR S, ASHFAQ A, et al. Performance optimization of lead-free MASnBr3 based perovskite solar cells by SCAPS-1D device simulation[J]. Solar Energy 2023, 249: 401-413.

    [18]

    JACOBSSON T J, TRESS W, CORREA-BAENA J P, et al. Room temperature as a goldilocks environment for CH3NH3PbI3 perovskite solar cells: the importance of temperature on device performance[J]. The Journal of Physical Chemistry C 2016, 120(21): 11382-11393.

    [19]

    YANG S, HAN Q, WANG L, et al. Over 23% power conversion efficiency of planar perovskite solar cells via bulk heterojunction design[J]. Chemical Engineering Journal 2021, 426: 131838.

    [20]

    GOGOI D, HOSSAIN M K, DAS T D, et al. Performance analysis of highlyefficient lead-free perovskite solar cells: a numerical insight[J]. Journal of Optics, 2024: 1-12.

    [21]

    LI E Z, GUO Y, LIU T, et al. Preheating-assisted deposition of solution-processed perovskite layer for an efficiency-improved inverted planar composite heterojunction solar cell[J]. RSC advances 2016, 6(37): 30978-30985.

    [22]

    BHATTARAI S, DAS T D. Optimization of carrier transport materials for the performance enhancement of the MAGeI3 based perovskite solar cell[J]. Solar Energy, 2021, 217: 200-207. DOI: 10.1016/j.solener.2021.02.002

    [23]

    GAN Y, QIU G, QIN B, et al. Numerical analysis of stable (FAPbI3) 0.85 (MAPbBr3) 0.15-based perovskite solar cell with TiO2/ZnO double electron layer[J]. Nanomaterials, 2023, 13(8): 1313. DOI: 10.3390/nano13081313

    [24]

    RAZA E, BHADRA J, ASIF M, et al. A numerical approach to study the effect of bandgap and electron affinity in HTL-free perovskite solar cells and design of two-terminal silicon/perovskite tandem solar cell[J]. Materials Today Communications, 2023, 37: 107383. DOI: 10.1016/j.mtcomm.2023.107383

    [25]

    RAI M, WONG L H, ETGAR L. Effect of perovskite thickness on electroluminescence and solar cell conversion efficiency[J]. The Journal of Physical Chemistry Letters, 2020, 11(19): 8189-8194. DOI: 10.1021/acs.jpclett.0c02363

  • 目的 

    在保证光电转换效率和稳定性的前提下,减少或替代铅的使用是钙钛矿太阳能电池(PSCs)绿色发展的重要任务。本文了设计了一种以n-MAGeI/p-MAGeI锗基钙钛矿同质结为光吸收层,CdZnS和MASnBr分别为电子传输层(ETL)和空穴传输层(HTL)结构的钙钛矿太阳能电池。

    方法 

    本文采用SCAPS-1D 软件模拟研究了TiO/MAGeI/Spiro-OMeTAD、CdZnS/MAGeI/MASnBr以及CdZnS/n-MAGeI/p-MAGeI/MASnBr三种结构PSCs的PCE,得出第三种结构的器件PCE最高后,利用Lambert-Beer定律其HTL与ETL厚度进行优化,最后对钙钛矿光吸收层的缺陷密度进行了优化。

    结果 

    基于n-MAGeI/p-MAGeI同质结钙钛矿光吸收层的光生载流子解离性能优于单层MAGeI钙钛矿的。CdZnS 作为ETL比传统TiO有更加匹配的能级位置,MASnBr作为HTL不仅可以起到空穴传输作用,还可以补充吸收钙钛矿层未吸收完的光子进而产生电子空穴对,从而提升电池的光电性能。对器件结构与缺陷密度进行优化后,得到 = 1.9069 V, = 15.1388 mA/cm, FF = 88.69%, PCE = 25.60%的光电性能,优于对比器件TiO/MAGeI/Spiro-OMeTAD 23.47%的PCE和CdZnS/MAGeI/MASnBr器件25.33%的PCE。

    结论 

    本文通过SCAPS-1D软件模拟研究了无铅锗基PSCs的各项光伏参数,发现CdZnS与MASnBr比传统的TiO与Spiro-OMeTAD材料更适合分别作为器件的ETL与HTL。与此同时,MASnBr作为HTL可实现有效吸收光子和促进空穴传输的双重功能,并模拟了ETL与HTL厚度对器件性能的影响。此外,针对同质结n-MAGeI/p-MAGeI结构在电池中的影响进行了研究,发现采用同质结结构可以有效减少电子-空穴复合,使载流子运输机制得到优化,从而改善电池性能。最后,通过对比n-MAGeI与p-MAGeI的缺陷浓度对器件性能的影响,发现n-MAGeI的缺陷浓度对电池性能的影响大于p-MAGeI缺陷浓度。考虑到实际情况,当两者缺陷浓度均为10cm时,电池器件各项性能指标达到最佳,最终得到 为1.9069 V, 为15.1388 mA/cm, FF为88.69%, PCE为25.60%的锗基PSCs。

  • 钙钛矿太阳能电池(PSCs)的光电转换效率(PCE)已经超过26%,是当前光伏领域的研究热点。然而,目前已得到的高效PSCs 大多基于MAPbI3、FAPbI3、CsPbI3等含铅钙钛矿。最近的研究表明,以MAPbI3、FAPbI3、MA0.1FA0.9Pb0.85Sr0.15I3分别作为吸收层,其模拟光电转换效率最高可达25.20%、27.49%、29%,虽然已经取得较高的PCE,但其光吸收层均含Pb2+,这与太阳能电池的绿色发展理念不符。因此,研究无铅高效钙钛矿光吸收材料也是当前PSCs研究的一个重要方向。

    本文了设计了一种以n-MAGeI3/p-MAGeI3锗基钙钛矿同质结为光吸收层,Cd0.5Zn0.5S和MASnBr3分别为电子传输层(ETL)和空穴传输层(HTL)结构的钙钛矿太阳能电池。采用SCAPS-1D 软件模拟研究了该器件的光电性能,发现n-MAGeI3/p-MAGeI3同质结钙钛矿光吸收层的光生载流子解离性能优于单层MAGeI3钙钛矿的。Cd0.5Zn0.5S 作为ETL比传统TiO2有更加匹配的能级位置,MASnBr3作为HTL不仅可以起到空穴传输作用,还可以补充吸收钙钛矿层未吸收完的光子进而产生电子空穴对,从而提升电池的光电性能。对器件结构与缺陷密度进行优化后,得到 VOC = 1.9069 V, JSC = 15.1388 mA/cm2, FF = 88.69%, PCE = 25.60%的光电性能,优于对比器件TiO2/MAGeI3/Spiro-OMeTAD 23.47%的PCE和Cd0.5Zn0.5S/MAGeI3/MASnBr3器件25.33%的PCE。

    优化厚度后三种器件结构对应的(a) J-V曲线;(b) QE曲线

图(6)  /  表(6)
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出版历程
  • 收稿日期:  2024-08-22
  • 修回日期:  2024-10-13
  • 录用日期:  2024-10-25
  • 网络出版日期:  2024-11-10

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