Mujtaba Ali, Khan M I, Amami Mongi, Alshahrani Dhafer O
Department of Physics, The University of Lahore Lahore 54000 Pakistan
Department of Chemistry, College of Science, King Khalid University P.O. Box 9004 Abha 61413 Saudi Arabia.
RSC Adv. 2025 Jul 15;15(31):25019-25029. doi: 10.1039/d5ra03446a.
Tungsten trioxide (WO), with strong electron affinity and recombination suppression, serves as an effective electron transport layer (ETL). Incorporating zinc oxide (ZnO) enhances its conductivity, forming a ZnO-WO composite with improved charge extraction and energy level alignment. The novelty of this study is to introduce ZnO-WO as an interlayer ETL in CsPbIBr-based perovskite solar cells, enabling superior device performance and stability. Both WO and ZnO-WO films were synthesized sol-gel spin coating. X-ray diffraction (XRD) confirmed the monoclinic phase for both films, with ZnO-WO exhibiting a larger crystallite size (67.7 nm) and lower dislocation density (2.18 × 10 lines per m). Raman spectroscopy revealed additional ZnO vibrational modes, indicating lattice reinforcement and enhanced structural integrity. Scanning electron microscopy (SEM) shows that ZnO-WO films have larger, more uniform grains and smoother morphology than WO, indicating improved film quality. UV-vis analysis showed a redshift and reduced bandgap (2.74 eV), while PL spectra indicated lower defect-related recombination. Time-resolved photoluminescence (TRPL) shows reduced average decay time for ZnO-WO, indicating faster carrier dynamics. Devices with ZnO-WO achieved a power conversion efficiency of 12.87% due to reduced charge transfer resistance (21 Ω) and higher recombination resistance (4605 Ω), as confirmed by electrochemical Impedance Spectroscopy (EIS). External Quantum Efficiency (EQE) of 95% further demonstrated enhanced charge collection, establishing ZnO-WO as a promising ETL for high-efficiency PSCs.
三氧化钨（WO）具有很强的电子亲和力并能抑制复合，可作为一种有效的电子传输层（ETL）。掺入氧化锌（ZnO）可提高其导电性，形成具有改善的电荷提取和能级排列的ZnO-WO复合材料。本研究的新颖之处在于将ZnO-WO作为基于CsPbIBr的钙钛矿太阳能电池的中间层ETL，从而实现卓越的器件性能和稳定性。WO和ZnO-WO薄膜均通过溶胶-凝胶旋涂法合成。X射线衍射（XRD）证实了两种薄膜均为单斜相，ZnO-WO表现出更大的微晶尺寸（67.7 nm）和更低的位错密度（每米2.18×10条线）。拉曼光谱揭示了额外的ZnO振动模式，表明晶格强化和结构完整性增强。扫描电子显微镜（SEM）显示，ZnO-WO薄膜比WO具有更大、更均匀的晶粒和更光滑的形貌，表明薄膜质量得到改善。紫外-可见分析显示红移和带隙减小（2.74 eV），而光致发光光谱表明与缺陷相关的复合降低。时间分辨光致发光（TRPL）显示ZnO-WO的平均衰减时间缩短，表明载流子动力学更快。通过电化学阻抗谱（EIS）证实，具有ZnO-WO的器件由于电荷转移电阻降低（21Ω）和复合电阻更高（4605Ω），实现了12.87%的功率转换效率。95%的外量子效率（EQE）进一步证明了电荷收集增强，确立了ZnO-WO作为高效PSC的有前途的ETL。
