Spray-cast multilayer perovskite solar cells with an active-area of 1.5 cm2

Abstract

We utilise spray-coating under ambient conditions to sequentially deposit compact-TiO2, mesoporous-TiO2, CH3NH3PbI(3−x)Clx perovskite and doped spiro-OMeTAD layers, creating a mesoporous standard architecture perovskite solar cell (PSC). The devices created had an average power conversion efficiency (PCE) of 9.2% and a peak PCE of 10.2%; values that compare favourably with control-devices fabricated by spin-casting that had an average efficiency of 11.4%. We show that our process can be used to create devices having an active-area of 1.5 cm2 having an independently verified efficiency of 6.6%. This work demonstrates the versatility of spray-coating as well as its potential as a method of manufacturing low-cost, large-area, efficient perovskite devices.

Coated and Printed Perovskites for Photovoltaic Applications

“…As a result, PCEs up to 17.8% were demonstrated for PSCs. Several studies have already demonstrated this, for instance, spray coating of PEDOT:PSS, [107] CuSCN, [108] Spiro-OMeTAD, [109] compact TiO 2 , [8,109] mesoporous TiO 2 , [109] and PCBM. [31] The study showed the significance of utilizing different boiling point solvents in various ratios to control the evaporation of solvents, but also relied on substrate heating at 120 °C.…”

“…[31] The study showed the significance of utilizing different boiling point solvents in various ratios to control the evaporation of solvents, but also relied on substrate heating at 120 °C. [109,110] Mohamad et al used PEDOT:PSS and PCBM as their HTL and ETL, respectively, achieving 9.9% efficient devices [110] while, Bishop et al achieved comparable device performance of 10.2% based on PSCs using spray-coated compact TiO 2 , mesoporous TiO 2 as ETLs and Spiro-OMeTAD as the HTL for their architecture. Moreover, the fabrication of 100 cm 2 large PV modules with an active area of 40 cm 2 and a PCE of up to 15.5% was realized.…”

“…[31] As a result, large perovskite grains exhibiting a low number of trap states were demonstrated using solvent mixtures of DMF and GBL in a ratio of 8:2. [109] In summary, spray coating is a very suitable technique for upscaling the perovskite thin-films. [31] Recently, Uličná et al reported the use of a slow-drying ink formulation that allowed an antisolvent approach to be used after spray coating.…”

“…Moreover, the fabrication of 100 cm 2 large PV modules with an active area of 40 cm 2 and a PCE of up to 15.5% was realized. [97,98,100] The main challenges of this technique are crystal-growth related thickness variations, [100,109] solution de-wetting [100] and nonuniform substrate coverage [48,100,110] arising from the surface tension driven coffee-ring [111] or Marangoni effects. In this study, the ink contained slow-drying solvents that were extracted in an antisolvent diethylether bath.…”

“…In this study, the ink contained slow-drying solvents that were extracted in an antisolvent diethylether bath. [99,100,109,110] Beyond control of process parameters, ink formulations using solvent mixtures and additives have been critical in addressing these issues. [106] The previous studies mentioned above covered the spray coating of the absorber layer only.…”