Effect of the functional inorganic material nickel oxide synthesized by solution method on the photoelectric performance of perovskite solar cells
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摘要: 功能无机材料氧化镍(NiOx)作为钙钛矿太阳能电池中最有前途的空穴传输材料之一,其有着高空穴迁移率、良好的稳定性、易于加工以及适合的费米能级等优点。但是,由于NiOx自身固有电导率低,Ni空位的电离能相当大,未掺杂的NiOx中空穴密度受到很大限制,加上孔洞的积累增加了载流子复合的可能,从而降低了有效的电荷收集。因此,优化NiOx薄膜的成膜质量是解决上述问题的关键。本文通过溶液法使用乙二醇甲醚(MEA)、乙醇(EA)和去离子水作为溶液,分别制备了DME-NiOx、EA-NiOx和NCs-NiOx薄膜,并在浓度调节范围内对基于NiOx的钙钛矿器件进行优化,最终得到了光电转化效率(PCE)为18.50%,开路电压(Voc)为1.034 V,短路电流(Jsc)为22.94 mA/cm2,填充因子(FF)为78%的最佳器件。Abstract: Functional inorganic material nickel oxide (NiOx) as one of the most promising hole transport materials in perovskite solar cells, it has the advantages of high hole mobility, good stability, easy processing and suitable Fermi level. However, due to the inherent low conductivity of NiOx itself, the ionization energy of Ni vacancies is quite large, and the hole density in undoped NiOx is greatly restricted. In addition, the accumulation of holes increases the possibility of carrier recombination, thereby reducing the effective charge collection. Therefore, opti-mizing the quality of NiOx film formation is the key to solving the above problems. In this paper, DME-NiOx, EA-NiOx and NCs-NiOx films were prepared by solution method using ethylene glycol methyl ether (MEA), ethanol (EA) and deionized water as solutions. And optimized the NiOx-based perovskite device within the concentration adjustment range. In the end, the best device with a photoelectric conversion efficiency (PCE) of 18.50%, an open circuit voltage (Voc) of 1.034 V, a short circuit current (Jsc) of 22.94 mA/cm2 and a fill factor (FF) of 78% is obtained.
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图 3 不同NiOx上钙钛矿薄膜的SEM形貌图及其XRD图谱: DME-NiOx (a)、EA-NiOx (b)和NCs-NiOx (c)上钙钛矿的SEM图像;DME-NiOx (d)、EA-NiOx (e)和NCs-NiOx (f)
上钙钛矿的XRD图谱 Figure 3. SEM morphology and XRD patterns of perovskite films on different NiOx: SEM images of perovskite on DME-NiOx (a), EA-NiOx (b) and NCs-NiOx (c);
XRD patterns of perovskite on DME-NiOx (d), EA-NiOx (e) and NCs-NiOx (f) 图 5 不同浓度DME-NiOx下钙钛矿薄膜的光学表征: (a)吸收强度;(b)吸收边;(c)荧光猝灭;(d)荧光寿命;(e)透过率;(f)方块电阻
Figure 5. Optical characterizations of perovskite films at different concentrations of DME-NiOx: (a) Absorption intensity; (b) Absorption edge; (c) Fluorescence quenching; (d) Fluorescence lifetime; (e) Transmittance; (f) Sheet resistance
表 1 不同类型NiOx的制备方法及制备条件
Table 1. Preparation methods and preparation conditions of different types of NiOx
Sample Raw materials Solvent Concentration/(mol·L−1) Preparation conditions DME-NiOx Nickel(II) acetate tetrahydrate Methoxyethanol 0.1 5000 r/min 50 s, 350℃ 90 min EA-NiOx Nickel(II) acetate tetrahydrate Ethanol 20 5000 r/min 50 s, 350℃ 90 min NCs-NiOx Nickel(II) nitrate hexahydrate Deionized water 20 3000 r/min 40 s, 100℃ 60 min Note: DME-NiOx, EA-NiOx, NCs-NiOx—Prepared by solution method using ethylene glycol methyl ether (MEA), ethanol (EA) and deionized water as solutions. 表 2 不同NiOx浓度下的Voc、Jsc、FF及PCE
Table 2. Voc, Jsc, FF and PCE under different NiOx concentrations
Sample Voc /V Jsc/
(mA·cm−2)FF/% PCE/% NCs-NiOx 1.015 17.93 76.17 13.96 EA-NiOx 1.036 19.23 76.95 15.34 DME-NiOx 0.05 mol/L 1.027 20.45 79.00 16.60 DME-NiOx 0.075 mol/L 1.043 21.36 79.29 17.68 DME-NiOx 0.1 mol/L 1.034 22.94 78.01 18.50 DME-NiOx 0.125 mol/L 1.024 19.99 78.64 16.10 Notes: Voc—Open-circuit voltage; Jsc—Short-circuit current density; FF—Fill factor; PCE—Power conversation efficiency. -
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