Figure 1 (a) Molecular structure and ESP of PbS, NHI and NHS materials. Charge diagrams of additives interacted with (b) FAI and (c) Pb-I framework in perovskite lattices. FTIR spectra of (d) pure PbS, PbS+FAI and PbS+PbI2 powders; (e) pure NHI, NHI+FAI and NHI+PbI2 powders; (f) pure NHS, NHS+FAI and NHS+PbI2 powders. ToF-SIMS depth profiles of PbI+, Ni+, NH4+ and SCN- species in the (g) pristine film and (h) NHS film.
Figure 2 In-situ UV-Vis absorption mapping of perovskite films during the (a) spin-coating and (b) thermal annealing process. Evolution of absorption peak intensity (c) at 500 nm for perovskite films during spin-coating process, (d) at 650 nm for perovskite films during thermal annealing process. Evolution of PL intensity at 750 nm for perovskite films (e) during spin-coating process and (f) thermal annealing process. (g) Crystallization dynamics schematic diagram of the pristine and NHS perovskite films.
Figure 3 Top-view SEM images of (a) pre-cast and (b) final perovskite films. (c) Statistical grain sizes, (d) XRD patterns, (e) UV–vis absorption spectrum, (f) PL spectra and (g) PL lifetime in PL mapping images of final perovskite films.
Figure 4 (a) SCLC analyses of final perovskite films. (b) TPC curves, (c) TPV curves, (d) dark J-V curves, (e) Nyquist plots and (f) M-S plots of final PSCs.
Figure 5 (a) J-V curves of champion PSCs with active area of 0.07 cm2. (b) Forward and reverse scanned J-V curves of the champion pristine and NHS devices. (c) PCE and (d) Voc statistic distributions of 20 independent PSCs of the pristine device and the NHS device. (e) EQE spectrum and (f) Steady-state output performance of the pristine device and target device. (g) moisture stability and (h) thermal stability test result of the pristine device and target device.
【全文速览】
近日，西安电子科技大学集成电路学部张春福教授团队青年教师董航在国际一流期刊Advanced Materials发表重要研究成果。该研究针对钙钛矿太阳能电池中薄膜缺陷导致的非辐射载流子复合和开路电压损失这一关键科学问题，创新性地提出了一种"配体辅助结晶动力学调控策略"。通过在钙钛矿前驱体中引入硫氰酸根（SCN-）和挥发性铵根（NH4+）双配体系统，研究团队成功实现了对薄膜成核和结晶过程的同步精准调控。研究表明，NH4+配体通过与Pb-I框架之间的强相互作用可促进薄膜快速成核，SCN-配体则通过FA+阳离子占位有效延缓了薄膜晶体生长速率，二者协同作用使得制备的钙钛矿薄膜具有更大的晶粒尺寸、更高的结晶度、更有序的表面形貌以及更低的残余应变。特别值得关注的是，残留SCN-配体还能有效钝化界面深能级缺陷。基于该策略制备的p-i-n结构器件实现了26.13%的转换效率，开路电压为1.2305 V，达到理论极值的96.13%，电压损失仅0.3195 V，创下同类器件最低记录。同时，器件表现出卓越的环境稳定性，在40-50%湿度下保存2016小时后保持92.24%的初始效率，85 ℃高温下存储1008小时后仍能保持初始效率的83.07%。这项突破性研究为钙钛矿薄膜质量控制和器件性能提升提供了新范式，对推动光伏技术产业化发展具有重要指导意义。论文第一作者为助理研究员董航，通讯作者为陈大正副教授、中石油深圳新能源研究院有限公司张晓珊助理研究员和张春福教授。
原文链接：http://advanced.onlinelibrary.wiley.com/doi/10.1002/adma.202511111
