高分子PVP添加剂对钙钛矿太阳电池稳定性的提升

doi:10.15541/jim20180172

摘要/Abstract

摘要：

作为一类新型薄膜太阳能电池, 近年来钙钛矿太阳电池的发展十分迅速, 其效率已接近商业化硅基太阳能电池, 但是钙钛矿薄膜在空气中稳定性较差, 严重限制了其进一步的商业化应用。本研究通过在钙钛矿薄膜中添加聚4-乙烯吡啶(PVP)来增强钙钛矿薄膜在空气中的稳定性。通过形貌、结构及性能测试, 发现相比于未添加PVP的钙钛矿薄膜, 添加PVP的钙钛矿薄膜形貌更均匀致密。添加0.4wt% PVP将钙钛矿太阳电池的光电效率从6.09%提升到13.07%, 而且, 存放在相对湿度超过50%的空气中, 其电池效率衰减为一半的时间由原来的3 d延长到3 w, 但是过多的PVP添加量会导致PbI₂与CH₃NH₃I反应不完全。添加PVP工艺进一步优化后, 有望用于大面积、高稳定性的钙钛矿薄膜的制备。

关键词: 钙钛矿太阳能电池, 稳定性, 聚4-乙烯基吡啶, 高分子添加剂

Abstract:

As a type of novel thin film solar cells, perovskite solar cells develope sharply within a decade, which efficiency has approached to that of the commercial silicon solar cells. However, its poor stability in the air has limited the further practical application. Herein, we achieve uniform sable perovskite films under open environment by adding some poly 4-vinylpyridine (PVP). The morphology, structure and performance test results show that the perovskite films added with PVP were more compact and uniform than the bare one. Moreover, the assembled solar cell with 0.4wt% PVP exhibited highly reproducible efficiencies up to 13.07%, much higher than that of 6.09% for the controlled one. When restored in the air with approximately 50% relative humidity in the absence of encapsulation, its efficiency decay time to a half from 3 d for bare one extended to 3 w. However, high PVP additives result in incomplete reaction between PbI₂ and CH₃NH₃I. If the above mentioned process is further optimized, is expected to be applied to the large-scale preparation of more stable perovskite film.

Key words: perovskite solar cell, stability, poly 4-vinylpyridine, polymer additive

中图分类号:

TQ174

熊浩, 张渤昕, 贾巍, 张青红, 谢华清. 高分子PVP添加剂对钙钛矿太阳电池稳定性的提升[J]. 无机材料学报, 2019, 34(1): 96-102.

XIONG Hao, ZHANG Bo-Xin, JIA Wei, ZHANG Qing-Hong, XIE Hua-Qing. Polymer PVP Additive for Improving Stability of Perovskite Solar Cells[J]. Journal of Inorganic Materials, 2019, 34(1): 96-102.

图/表 10

图1 添加不同含量PVP的PbI2薄膜的SEM照片

Fig. 1 Surface SEM images of PbI2 films on the glass with or without polymer modification (a) Without PVP; (b) 0.2wt% PVP; (c) 0.4wt% PVP; (d) 0.6wt% PVP; (e) 0.8wt% PVP

图2 添加不同含量PVP的钙钛矿薄膜的SEM照片

Fig. 2 Surface SEM images of perovskite films with various concentration of PVP (a) Without PVP; (b) 0.2wt% PVP; (c) 0.4wt% PVP; (d) 0.6wt% PVP; (e) 0.8wt% PVP

图3 添加不同含量PVP的薄膜紫外-可见吸收光谱图

Fig. 3 UV-visible absorption spectra of films in presence of varying concentration of PVP (a) PbI2 films; (b) CH3NH3PbI3 films

图4 添加不同含量PVP的钙钛矿薄膜的荧光光谱图

Fig. 4 Steady state photoluminescence (PL) spectra of perovskite films doped with various concentration of PVP on the glass

图5 添加不同含量PVP的新鲜钙钛矿薄膜的XRD图谱; 实物照片中PVP添加量从下到上依次为0, 0.2wt%, 0.4wt%, 0.6wt%, 0.8wt% (左边为碘化铅, 右边为钙钛矿)

Fig. 5 XRD patterns of fresh perovskite films doped with PVP of various quantities; The optical photos from bottom to top in the inserted are 0, 0.2wt%, 0.4wt%, 0.6wt%, 0.8wt% PVP (PbI2 on the left, perovskite on the right)

图6 在空气中放置3 w后添加不同含量PVP的钙钛矿薄膜的XRD图谱; 实物照片中PVP添加量从下到上依次为0, 0.2wt%, 0.4wt%, 0.6wt%, 0.8wt%(左边为碘化铅右边为钙钛矿)

Fig. 6 XRD patterns of CH3NH3PbI3 doped with PVP of various quantities after three weeks in the air; The optical photos from bottom to top in the inserted are 0, 0.2wt%, 0.4wt%, 0.6wt%, 0.8wt% PVP, respectively (PbI2 on the left, perovskite on the right)

图7 添加不同含量PVP的钙钛矿太阳能电池的J-V曲线

Fig. 7 Photocurrent density-voltage (J-V) curves of the PSCs doped with various concentration of PVP

表1 现场制备的添加不同含量PVP的钙钛矿太阳能电池性能参数

Table 1 The parameters of as-prepared perovskite solar cells doped with various concentration of PVP

Sample	V_oc/V	J_sc/(mA·cm^-2)	FF/%	PCE/%
Without PVP	0.95	16.17	39.40	6.09
0.2wt% PVP	1.00	19.14	46.10	8.86
0.4wt% PVP	1.04	19.60	64.00	13.07
0.6wt% PVP	1.05	17.39	67.77	12.34
0.8wt% PVP	1.04	14.83	67.38	10.42

表2 在空气中放置3 d的添加不同含量PVP的钙钛矿太阳能电池性能参数

Table 2 The parameters of perovskite solar cells doped with various concentration of PVP after three days in the air

Sample	V_oc/V	J_sc/(mA·cm^-2)	FF/%	PCE/%
Without PVP	1.09	12.05	31.64	4.17
0.2wt% PVP	0.78	16.75	48.36	6.33
0.4wt% PVP	1.04	21.05	53.05	11.60
0.6wt% PVP	0.99	21.44	47.12	10.02
0.8wt% PVP	0.84	17.20	66.10	9.52

表3 在空气中放置3 w的添加不同含量PVP的钙钛矿太阳能电池性能参数

Table 3 The parameters of perovskite solar cells doped with various concentration of PVP after three weeks in the air

Sample	V_oc/V	J_sc/(mA·cm^-2)	FF/%	PCE/%
Without PVP	0.95	6.18	26.35	1.55
0.2wt% PVP	1.03	15.53	29.75	4.75
0.4wt% PVP	0.80	15.12	54.84	6.63
0.6wt% PVP	0.82	10.88	68.36	6.11
0.8wt% PVP	0.97	21.13	34.29	7.04

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