铜膜碘化法制备p型CuI薄膜及其用作空穴传输层的反型钙钛矿电池性能

doi:10.15541/jim20150455

摘要/Abstract

摘要：

γ相碘化亚铜(γ-CuI)是一种带隙为3.1 eV的p型半导体材料, 适合应用于发光二极管和太阳能电池等光电子器件。本研究利用简单的铜膜碘化法制备了CuI薄膜, 探究了碘化时间、温度及铜/碘比等生长条件对其透明导电性能的影响。在最优碘化时间(30 min)和碘化温度(120℃)下, 制备出了高透过率(可见光范围>75%)、导电性能好(电阻率4.4×10^-2 Ω·cm)的CuI薄膜。利用CuI薄膜作为空穴传输层, 组装了CuI/CH₃NH₃PbI₃/PCBM反型平面钙钛矿电池, 获得的最高光电转换效率为8.35%, 讨论了CuI薄膜透明导电性能对钙钛矿电池光电转换效率的影响机理。

关键词: 碘化亚铜, 铜膜碘化法, 透明导电, 反型钙钛矿太阳能电池

Abstract:

γ-phase copper iodide (γ-CuI) is a wide bandgap p-type semiconductor with a band gap of 3.1 eV, which is suitable for optoelectronic devices like light-emitting diodes and solar cells. A simple and convenient method of iodination of copper film to prepare CuI film was reported. The effects of iodination time, reaction temperature, and copper/iodine ratio on the transparent and conductive properties of CuI film were explored. CuI films with high transmittance over 75% in the visible range and low resistivity of 4.4×10^-2 Ω·cm were grown under the optimized iodination time (30 min) and iodination temperature (120℃). The CuI films were adopted as hole transporting layers for CuI/CH₃NH₃PbI₃/PCBM inverted planar perovskite solar cell and a maximum photovoltaic efficiency of 8.35% was obtained. The influences of the transparent and conductive properties of CuI films on the solar cell photovoltaic efficiency were also discussed.

Key words: CuI, iodination of copper, transparent and conductive property, inverted perovskite solar cell

中图分类号:

O472

刘畅, 苑帅, 张海良, 曹丙强, 吴莉莉, 尹龙卫. 铜膜碘化法制备p型CuI薄膜及其用作空穴传输层的反型钙钛矿电池性能[J]. 无机材料学报, 2016, 31(4): 358-364.

LIU Chang, YUAN Shuai, ZHANG Hai-Liang, CAO Bing-Qiang, WU Li-Li, YIN Long-Wei. p-type CuI Films Grown by Iodination of Copper and Their Application As Hole Transporting Layers for Inverted Perovskite Solar Cells[J]. Journal of Inorganic Materials, 2016, 31(4): 358-364.

图/表 9

图1 优化真空沉积制备条件下, 所制备铜薄膜的(a)SEM照片和(b) XRD图谱

Fig. 1 (a) SEM image and (b) XRD pattern of copper film grown under optimized vacuum thermal deposition condition

表1 铜膜碘化过程实验参数表

Table 1 Growth condition of iodination of copper film

Sample No.	Reaction time/ min	Reaction temperature/℃	Cu/I ratio
1	15	120	1:1
2	30	120	1:1
3	45	120	1:1
4	60	120	1:1
5	30	120	1:1
6	30	140	1:1
7	30	160	1:1
8	30	180	1:1
9	30	140	1:1
10	30	140	1:10
11	30	140	1:100

图2 不同铜/碘比碘化得到的CuI薄膜的SEM照片(a~c)及其对应的XRD图谱(d)和透过光谱(e)

Fig. 2 SEM images of CuI films deposited with different Cu/I ratios and corresponding XRD patterns and optical transmission spectra (a) 1:1, (b) 1:10, (c) 1:100

表2 不同铜/碘比碘化制备CuI薄膜的霍尔测试结果

Table 2 Hall effect data of CuI films grown with different Cu/I ratios

Cu/I ratio	Resistivity/(10^-2 Ω·cm)	Mobility/(cm²·V^-1·s^-1)
1:1	8.9	8.6
1:10	8.2	13.5
1:100	11.1	1.5

图3 不同碘化时间和碘化温度制备的CuI薄膜表面的SEM照片

Fig. 3 Surface morphology SEM images of CuI films grown under different iodination temperature and iodination time (a) 15 min, 120℃; (b) 30 min, 120℃; (c) 45 min, 120℃; (d) 30 min, 160℃

图4 铜/碘质量比为1:10时, 不同碘化时间(a)及不同碘化温度(b)制备条件下CuI薄膜的透射光谱

Fig. 4 Influence of iodination temperature (a) and iodination time (b) on the transmission property of CuI film with Cu/I ratio of 1:10

表3 不同碘化时间和碘化温度制备的碘化亚铜薄膜的霍尔测试结果

Table 3 Hall effect data of CuI films grown under different iodination temperature and time

Iodination time/temperature	Resistivity/ (10^-2 Ω·cm)	Mobility/ (cm²·V^-1·s^-1)
15 min/120℃(Ⅰ)	9.9	14.9
30 min/120℃(Ⅱ)	4.4	29.6
45 min/120℃(Ⅲ)	7.1	17.1
30 min/160℃(Ⅳ)	13.9	9.5

图5 (a)基于CuI薄膜的钙钛矿电池结构示意图及(b)对应断面SEM照片。用不同碘化亚铜薄膜作为空穴传输层的钙钛矿电池的电流密度-电压曲线(c)和外量子效率曲线(d)

Fig. 5 (a) Schematic diagram and (b) typical SEM image of CuI film based planar perovskite solar cell. (c) Current density-voltage (J-V) characteristic curves and (d) EQE curves of the perovskite solar cells assembled with different CuI films as hole transporting layers. Curves labeled with (I~IV) correspond to samples (I~IV) in Table 3 grown under different iodination temperature and time

表4 不同碘化亚铜薄膜用作空穴传输层时钙钛矿电池的性能参数

Table 4 Corresponding photovoltaic properties of perovskite solar cells (I-IV) with different CuI as hole transporting layer

Devices	V_OC/V	J_SC/(mA·cm^-2)	FF/%	η /%
I	0.92	14.26	53.73	7.05
II	0.93	15.33	58.51	8.35
III	0.89	12.84	54.01	6.17
IV	0.86	8.45	51.70	3.75

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