Highly compact TiO₂layer for efficient hole-blocking in perovskite solar cells

Abstract

A uniform and pinhole-free hole-blocking layer is necessary for high-performance perovskite-based thin-film solar cells. In this study, we investigated the effect of nanoscale pinholes in compact TiO2 layers on the device performance. Surface morphology and film resistance studies show that TiO2 compact layers fabricated using atomic layer deposition (ALD) contain a much lower density of nanoscale pinholes than layers obtained by spin coating and spray pyrolysis methods. The ALD-based TiO2 layer acts as an efficient hole-blocking layer in perovskite solar cells; it offers a large shunt resistance and enables a high power conversion efficiency of 12.56%.

Control of organic–inorganic halide perovskites in solid-state solar cells: a perspective

“…However, different from DSCs [59][60][61][62][63][64], the nanostructure of the photoanode material is not that important, because the organohalide lead perovskite itself has a much higher absorbance coefficient [65] and thus even a thin layer of around 100 nm is enough to obtain a considerable high performance [66]. On the other hand, the barrier layer or the underlayer of TiO 2 plays a more crucial role in the performance of solidstate solar cells [67][68][69]. Different methods or techniques applied to make a pin-hole free compact layer have been thoroughly studied previously for dye-sensitized solid-state solar cells [70].…”

In-situ fabrication of dual porous titanium dioxide films as anode for carbon cathode based perovskite solar cell

“…The TiO 2 compact layer also plays an important role in the PSC device performance by blocking holes and sealing recombination pathways [71]. We further investigated the effect of TiO 2 compact layer on the C-PSC performance.…”

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“…Effect of various deposition techniques of depositing compact TiO2 (spin coating, spray pyrolysis, and atomic layer deposition) on device performance was well studied by Han et al [42] In addition to TiO2 compact layer, ZnO and SnO2 were also studied for hole-blocking layers or electron-transport layer for high-efficiency devices [19,43] . In 2014, Zhu and his co-workers reported for the first time a compact layer free PSC, where they used an alkali solution for modification of ITO glass and observed 15.1% of efficiency [44] .…”