近日，昆明理工大学材料科学与工程学院陈江照教授团队在国际材料与能源权威期刊ACS Energy Letters上以“Synergistically stabilizing hole transport layer and dual interface enables high-performance perovskite solar cells”为题发表最新研究成果，该研究工作得到国家自然科学基金面上、兵团重点领域科技攻关计划等项目的资助。
高效率的n-i-p型钙钛矿太阳能电池（PSCs）通常依赖于掺杂Li-TFSI和tBP的有机空穴传输层（HTL）。然而，Li+和卤素离子的迁移和扩散以及tBP的挥发严重制约PSCs的长期运行稳定性。鉴于此，陈江照教授团队采用l -谷氨酸二苄基酯- 4甲苯磺酸盐（GADET）同时调控HTL和埋底界面，通过固定Li+、tBP和卤素离子及钝化双界面缺陷，稳定HTL，减少界面能损失。GADET通过苯磺酸阴离子与Li+的离子键相互作用抑制了Li+离子的扩散，而-NH3+与tBP形成氢键可以抑制tBP的挥发。此外，通过钝化未配位Pb2+和卤素空位缺陷，能够有效抑制卤素离子迁移和界面陷阱诱导的非辐射复合。协同优化的器件实现了25.06%的冠军功率转换效率（认证PCE为24.08%）。目标器件分别在35-45%相对湿度条件下老化3000 h、65℃热老化2000 h、一个太阳模拟光连续照射1200 h后分别保持了原始效率的95.02%、91.21%和80.23%。
Fig. 1 Promoting doping and its mechanism investigation via introducing GADET. (a) ESR spectra of the Spiro-OMeTAD films without and with GADET doping. (b) 7Li NMR of the LiTFSI solution without and with GADET. (c) Doping efficiency enhancement and HTL stabilization mechanisms upon incorporating GADET. (d) UV-vis spectra of the Spiro-OMeTAD solutions with gradual addition of GADET (without LiTFSI and tBP). The solutions were prepared in the nitrogen glove box. The measurement was conducted in ambient condition. (e) J-V curves of the champion devices based on the Spiro-OMeTAD solutions containing different concentrations of GADET (without LiTFSI and tBP).
Fig. 2 Stabilizing HTL and Ag electrode via suppressing Li+ and halide ions migration and diffusion by GADET modification. TOF-SIMS depth distribution of perovskite/HTL films without (a) and with (b) GADET which were aged under light and heat at 60 ℃ for 240 h in a nitrogen filled glovebox. Cross-sectional SEM images of the HTLs without (c) and with (d) GADET after aging under light and heat at 60 ℃ for 240 h in a nitrogen filled glovebox, (e) Schematic diagram of halogen ion migration and AgI formation in the devices based on pristine HTL.
Fig. 3 Modulation mechanisms of buried interface via GADET. (a) XPS spectra of Sn 3d from the SnO2 films with and without GADET treatment. (b) FTIR spectra of the pristine and treated SnO2 films with GADET. XPS spectra of (c) Pb 4f and (d) O 1s from the perovskite films with and without GADET. (e) Schematically illustrated diagram of the buried interface defect passivation by GADET.
Fig. 4 Carrier dynamics study. (a) SSPL and (b) TRPL spectra of the perovskite films deposited on non-conductive glass without and with bottom surface passivation, top surface passivation or synergistic passivation via GADET. (c) Defect density for the perovskite films without and with bottom surface passivation, top surface passivation or dual surface passivation by GADET. (d) VOC versus light intensity for the devices with or without modification. (e) TPV curves for the control and modified PSCs. (f) Energy band diagram of all device components.
Fig. 5 J-V curves of the champion devices (a) without and (b) with synergistic modification based on perovskite composition Rb0.02(FA0.95Cs0.05)0.98PbI2.91Br0.03Cl0.06 (0.1 cm2).(c) Moisture stability of the unencapsulated devices aged under a relative humidity of 35-45% at room temperature in the dark. (d) Thermal stability of the unencapsulated devices kept at 65 ℃ in a nitrogen-filled glovebox in the dark. (e) Light stability of the unencapsulated devices under an illumination of 100 mW/cm2 provided by white light LED at room temperature in the nitrogen-filled glovebox (5 devices).
文章链接：
Dongmei He#, Danqing Ma#, Ru Li#, Baibai Liu, Qian Zhou, Hua Yang, Shirong Lu, Zhengfu Zhang, Caiju Li, Xiong Li, Liming Ding, Jing Feng, Jianhong Yi, Jiangzhao Chen*. Synergistically stabilizing hole transport layer and dual interface enables high-performance perovskite solar cells. ACS Energy Letters 2024, 9, 2615-2625.
https://pubs.acs.org/doi/10.1021/acsenergylett.4c00816
（供稿：材料学院）