近日，重庆大学光电工程学院陈江照研究员团队在国际知名学术期刊ACS Applied Materials & Interfaces（TOP期刊）上发表题为《Crystal Orientation Modulation and Defect Passivation for Efficient and Stable Methylammonium-Free Dion-Jacobson Quasi-2D Perovskite Solar Cells》的文章。相对于Ruddlesden–Popper（RP）型二维钙钛矿Dion-Jacobson (DJ)型钙钛矿因为具有更好的结构稳定性、更好的载流子输运能力等优点而得到日益剧增的关注。过去报道的大多数二维钙钛矿均采用甲铵阳离子（MA⁺），MA⁺基钙钛矿常常表现出差的光、湿及热稳定性，阻碍了钙钛矿太阳能电池的商业化应用。在本工作中，我们使用稳定性更好的甲脒阳离子（FA⁺）来取代MA⁺，不仅提高了稳定性而且有效拓宽了光谱吸收范围。为了进一步改善钙钛矿薄膜的质量，我们报道了一种多功能添加剂策略，成功制备出高质量无甲铵DJ型准二维钙钛矿薄膜。该策略即通过在钙钛矿前驱液中引入N,N'-羰基二(1,2,4-三氮唑)（CDTA）来实现。通过CDTA改性，实现了相分布控制、晶粒尺寸增加、结晶度改善、晶粒取向调控及缺陷钝化。经过改性后形成了梯度的相分布，进而获得梯度能带排列，有益于载流子传输与提取。改善的晶粒取向能够促进载流子传输与收集。结果，CDTA改性的器件实现了16.07%的功率转换效率，该效率是无甲铵DJ型准二维钙钛矿太阳能电池迄今为止报道的最高效率之一。未封装CDTA改性的器件在一个太阳光老化360小时后保持初始效率的92%，在60 °C老化360小时后保留初始效率的86%。该研究成果为钙钛矿太阳能电池的商业化奠定了坚实的基础。

Figure 1. (a) Schematical illustration of the device structure employed in this work. (b) Chemical structure of CDTA molecule. (c) Schematical illustration of the chemical interation between CDTA and perovskite. (d) J-V curves and (e) IPCE spectra of the champion control and target devices. J-V curves were measured in reverse scan (RS) at a scan rate of 100 mV/s under simulated AM 1.5G one sun illumination of 100 mW/cm². (f) Time-dependent steady-state current density and PCE for the best-performing control and target devices measured at the maximum power point.

文献链接：Pengyu Su,^# Le Bai,^# Huan Bi, Baibai Liu, Dongmei He, Wenqi Wang, Xiaobing Cao,* Shi Chen, Donghwa Lee, Hua Yang, Zhigang Zang, Jiangzhao Chen*. Crystal orientation modulation and defect passivation for efficient and stable methylammonium-free Dion-Jacobson quasi-2D perovskite solar cells. ACS Applied Materials & Interfaces 2021: https://pubs.acs.org/doi/10.1021/acsami.1c05498