TiO2 colloid-based compact layers for hybrid lead halide perovskite solar cells. (June 2017)

• Record Type: Journal Article
• Authors: Prathapani, Sateesh; More, Venumadhav; Bohm, Siva; Bhargava, Parag; Yella, Aswani; Mallick, Sudhanshu
• Is Part Of: Applied materials today. Volume 7(2017)
• Page Start: 112
• Page End: 119
• Publication Date: 2017-06
• Subjects: TiO2 colloids -- TiO2 nanoparticles -- Titania nanoparticles -- TiO2 compact layer for perovskite solar cells; Materials science -- Periodicals; Materials -- Research -- Periodicals; 620.1105
• DOI: 10.1016/j.apmt.2017.01.009
• Languages: English
• ISSNs: 2352-9407

Abstract

Graphical abstract: Highlights: TiO2 colloidal solution is prepared. Compact TiO2 films are formed on FTO (c-TiO2 /FTO) by using as-prepared colloids. The blocking nature of colloidal-based sintered c-TiO2 is confirmed by cyclic voltammetry. Perovskite solar cell devices are made successful in ambient conditions by using TiO2 colloidal-based compact layers. Abstract: In this report, we present a simple method of TiO2 colloidal preparation and its application to form compact conformal TiO2 (c-TiO2 ) layers on transparent conducting substrates. The synthesized colloid has ∼5 nm particle size distribution and is stable over a period exceeding one year. The blocking nature of c-TiO2 is evaluated by the method of cyclic voltammetry using Spiro-OMeTAD as the redox probe. This method of c-TiO2 preparation is successfully employed in the fabrication of hybrid perovskite solar cells. The critical requirement of c-TiO2 colloid-based compact layer as hole-blocking material is justified with the realization of photo-conversion efficiencies of 8.08% for small active areas of 0.07 cm 2 and 7.52% with relatively large active areas of 0.23 cm 2 in one-step method. In two-step sequential deposition method, a photo-conversion efficiency of 4.61% is achieved over relatively large active area of 0.64 cm 2 . Our observations suggest that c-TiO2 formation by TiO2 colloid can be an alternative potential route to approach for perovskite solar cell fabrication. All device processing is carried out in ambient air of relative humidity 40 ± 5% at room temperature.