title: Perovskite photovoltaics featuring solution-processable TiO2 as an interfacial electron-transporting layer display to improve performance and stability.
abstract: In this study we used solution-processable crystalline TiO2 nanoparticles as an interfacial modified layer between the active layer and aluminum cathode to fabricate CH3NH3PbI3/PCBM-based planar heterojunction perovskite photovoltaic (PPV) devices. We optimized the performance of the PPV device prepared without TiO2 by varying the preheating temperature of the indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) (PEDOT) substrate, obtaining a power conversion efficiency (PCE) of 6.3% under simulated AM 1.5 G irradiation (100 mW cm(-2)). After incorporating the TiO2 layer, we obtained a much higher PCE of 7.0%. The TiO2-containing PPV device exhibited extremely high stability (retaining ∼96% of its PCE after 1000 h) under long-term storage in a dark N2-filled glove box; the unencapsulated device retained approximately 80% of its original efficiency (T80) after 1 week under ambient conditions (ISOS-D-1; defined as 23 °C/50% RH). In contrast, the normal device was sensitive to ambient conditions with a value of T80 at only 3 h. We attributed the improved device performance (PCE, stability) to the enhanced electron transporting, hole blocking, and barrier properties arising from the presence of the TiO2 layer.
authors.affiliation: Department of Materials Engineering, Ming Chi University of Technology, 84 Gunjuan Road, Taishan, New Taipei City, 243, Taiwan. yyyu@mail.mcut.edu.tw cpchen@mail.mcut.edu.tw.
authors.forename: Yang-Yen
authors.initials: YY
authors.lastname: Yu
authors.forename: Rih-Sheng
authors.initials: RS
authors.lastname: Chiang
authors.forename: Hsiang-Lin
authors.initials: HL
authors.lastname: Hsu
authors.forename: Chun-Chen
authors.initials: CC
authors.lastname: Yang
authors.forename: Chih-Ping
authors.initials: CP
authors.lastname: Chen