Vacuum co-deposited CH3NH3PbI3 films by controlling vapor pressure for efficient planar perovskite solar cells

Co‐Evaporated MAPbI3 with Graded Fermi Levels Enables Highly Performing, Scalable, and Flexible p‐i‐n Perovskite Solar Cells

“…Most of the optical, morphological, and structural properties of the MAPbI 3, during the co-evaporation process, are usually controlled by fixing the main sublimation parameters such as the sources' temperatures, [9,53] substrate temperature, [40,54] and the chamber background pressure. [55,56] In this work, instead, we propose an alternative way to control the MAPbI 3 deposition process where the chamber background pressure is slowly decreased during the whole perovskite growth. Since the background pressure is mainly related to the low-molecularweight MAI partial pressure, its decrease will mainly affect the MAI deposition on the substrate.…”

“…This compositional gradient is created during the entire deposition process as the deposition rate of MAI is significantly affected by chamber pressure and the substrate temperature. [54,56] Indeed, keeping the PbI 2 and MAI temperatures constant during the evaporation of MAI can be slowly reduced as the chamber pressure decreases during the evaporation process. Therefore, graded MAPbI 3 film is formed due to MAI deficiency during the growth process.…”

Two-step MAPbI3 deposition by low-vacuum proximity-space-effusion for high-efficiency inverted semitransparent perovskite solar cells

“…In this context, a record efficiency of 20.8% was achieved using high vacuum conditions, (1x10 -6 mbar) by Perez del Rey et al 25 with a co-evaporation of MAI and PbI 2 for a 590 nm-thick layer of MAPbI 3 . More recently, Arivazhgan et al 26 have studied in detail the role of vapor pressure in a range of high-vacuum (HV) conditions between 5.6x10 -5 Torr and 5.6x10 -6 Torr finding the best condition at 3.3x10 -5 Torr that allowed a 350-thick MAPbI 3 layer achieving 15.74% cell efficiency Guo et al 27 used the well-known closed space sublimation (CSS) technique for deposition of organic materials to convert a pristine spin-coated PbI 2 into MAPI by sublimation of MAI powders at a short distance ( 1 mm). They obtained a best efficiency of 16.2% with a 4 mm 2 active area device.…”

Efficient, Hysteresis‐Free, and Flexible Inverted Perovskite Solar Cells Using All‐Vacuum Processing

“…[26,27] However, in terms of large-area devices and scale-up, vacuum techniques have more potential as the deposition of precursors can be controlled precisely much better than a solution method even without annealing the perovskite film. [28,29] There are several approaches under the vacuum category, thermal evaporation in one step [30] or two steps, [31] layer-by-layer deposition, [32,33] and chemical vapor deposition (CVD), [34] which can provide us high-quality perovskite films conformally deposited on any substrate with an extremely large area without any pinholes. [35][36][37][38] As a PSC consists of electrodes, the electron transporting layer (ETL), hole transporting layer (HTL), and perovskite absorber layer, all the layers have to be deposited by a vacuum approach to fabricate an all-vacuum-processed device.…”