Alaei Aida, Mohajerani Seyed Sepehr, Schmelmer Ben, Rubio Thiago I, Bendesky Justin, Kim Min-Woo, Ma Yichen, Jeong Sehee, Zhou Qintian, Klopfenstein Mia, Avalos Claudia E, Strauf Stefan, Lee Stephanie S
Department of Chemistry and Molecular Design Institute, New York University, New York, New York 10003, United States.
Department of Physics, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States.
ACS Appl Mater Interfaces. 2023 Dec 6;15(48):56127-56137. doi: 10.1021/acsami.3c09434. Epub 2023 Nov 21.
Perovskite nanowire arrays with large surface areas for efficient charge transfer and continuous highly crystalline domains for efficient charge transport exhibit ideal morphologies for solar-cell active layers. Here, we introduce a room temperature two-step method to grow dense, vertical nanowire arrays of formamidinium lead iodide (FAPbI). PbI nanocrystals embedded in the cylindrical nanopores of anodized titanium dioxide scaffolds were converted to FAPbI by immersion in a FAI solution for a period of 0.5-30 min. During immersion, FAPbI crystals grew vertically from the scaffold surface as nanowires with diameters and densities determined by the underlying scaffold. The presence of butylammonium cations during nanowire growth stabilized the active α polymorph of FAPbI, precluding the need for a thermal annealing step. Solar cells comprising α-FAPbI nanowire arrays exhibited maximum solar conversion efficiencies of >14%. Short-circuit current densities of 22-23 mA cm were achieved, on par with those recorded for the best-performing FAPbI solar cells reported to date. Such large photocurrents are attributed to the single-crystalline, low-defect nature of the nanowires and increased interfacial area for photogenerated charge transfer compared with thin films.
具有大表面积以实现高效电荷转移以及连续高度结晶区域以实现高效电荷传输的钙钛矿纳米线阵列展现出太阳能电池活性层的理想形态。在此，我们介绍一种室温两步法来生长致密的垂直甲脒碘化铅（FAPbI）纳米线阵列。通过将嵌入阳极氧化二氧化钛支架圆柱形纳米孔中的PbI纳米晶体浸入FAI溶液中0.5 - 30分钟，将其转化为FAPbI。在浸入过程中，FAPbI晶体从支架表面垂直生长为纳米线，其直径和密度由底层支架决定。纳米线生长过程中丁基铵阳离子的存在稳定了FAPbI的活性α多晶型，无需热退火步骤。包含α - FAPbI纳米线阵列的太阳能电池展现出大于14%的最大太阳能转换效率。实现了22 - 23 mA cm的短路电流密度，与迄今报道的性能最佳的FAPbI太阳能电池所记录的短路电流密度相当。如此大的光电流归因于纳米线的单晶、低缺陷性质以及与薄膜相比光生电荷转移的界面面积增加。
