A novel ball milling technique for room temperature processing of TiO2 nanoparticles employed as the electron transport layer in perovskite solar cells and modules

作者：Singh, Mriganka; Chiang, Chien-Hung; Boopathi, Karunakara Moorthy; Hanmandlu, Chintam; Li, Gang; Wu, Chun-Guey^*; Lin, Hong-Cheu^*; Chu, Chih-Wei^*

来源：Journal of Materials Chemistry A, 2018, 6(16): 7114-7122.

DOI：10.1039/c8ta00303c

• ORGANOMETAL HALIDE PEROVSKITES
• THIN-FILM
• EXTRACTION LAYER
• EFFICIENCY
• PERFORMANCE
• CH3NH3PBI3
• ENHANCEMENT
• STABILITY
• CARBON
• PHOTOCURRENT

Anatase titanium dioxide (an-TiO2) is often used as the electron transporting material (ETM) in planar-heterojunction perovskite solar cells (PSCs) because of its excellent semiconductor characteristics, outstanding optical transmittance, and suitable band structure. Herein, we report an inexpensive method for mass-scale production of TiO2 ETMs at room temperature (RT similar to 30 degrees C), involving the grinding of large clumps of an-TiO2 to form a suspension of TiO2 nanoparticles (NPs) in isopropyl alcohol for meso-superstructured PSCs. This process does not involve any chemical synthesis; it is a purely physical process. The lowest unoccupied molecular orbital (LUMO) of ground an-TiO2 NPs, estimated using ultraviolet photoelectron spectroscopy (UPS), was ca. 4.06 eV, which is a salient feature for the active layer. A regular perovskite solar cell (PSC) based on a CH3NH3PbI3 absorber and ground an-TiO2 ETL exhibited a champion power conversion efficiency (PCE) of 17.43% with an active area of 0.1 cm(2). The same ground an-TiO2 NPs were used to fabricate a large-area (designated area: 25.2 cm(2)) PSC and a PCE of 14.19% was achieved. PSC devices incorporating the ground an-TiO2 NP ETLs exhibited an attractive long-term device stability, with the PCE retaining approximately 85% of the initial values after 80 days.

• 出版日期2018-4-28
• 单位清华大学; 中国科学院; 长春大学; 中央民族大学; 香港理工大学