Ultrafast Low-Temperature Crystallization of Solar Cell Graded Formamidinium-Cesium Mixed-Cation Lead Mixed-Halide Perovskites Using a Reproducible Microwave-Based Process

Abstract

The control of morphology and crystallinity of solution-processed perovskite thin-films for solar cells is the key for further enhancement of the devices' power conversion efficiency and stability. Improving crystallinity and increasing grain size of perovskite films is a proven way to boost the devices' performance and operational robustness, nevertheless this has only been achieved with high-temperature processes. Here, we present an unprecedented low-temperature (<80°C) and ultrafast microwave (MW) annealing process to yield uniform, compact, and crystalline FA 0.83 Cs 0.17 Pb(I (1−x) Br x) 3 perovskite films with full coverage and micrometer-scale grains. We demonstrate that the nominal composition FA 0.83 Cs 0.17 PbI 1.8 Br 1.2 perovskite films annealed at 100 W MW power present the same band gap, similar morphology, and crystallinity of conventionally annealed films, with the advantage of being produced at a lower temperature (below 80°C vs 185°C) and during a very short period of time (∼2.5 min versus 60 min). These results open new avenues to fabricate band gap tunable perovskite films at low temperatures, which is of utmost importance for mechanically flexible perovskite cells and monolithic perovskite based tandem cells applications.

Perovskite Metal–Oxide–Semiconductor Structures for Interface Characterization

“…HI (109.4 µL) and HBr (54.6 µL) and the solution was stirred for 48 h at room temperature, according with the experimental procedure described elsewhere. [86] MOS Fabrication: For the MOS structures fabrication, radio frequency sputtering (room temperature, SnO 2 target with a diameter of 2″ (≈5 cm), bias voltage of 228 V, chamber pressure of 6.9 × 10 −3 mBar at 60 W with a deposition rate of 1.30 nm min −1 on a Kenosistec multitarget UHV sputtering system) was used to deposit a compact SnO 2 layer with a thickness of 20 and 30 nm. The SnO 2 layer was deposited onto FTO (Pilkington, TEC8), previously cleaned following a stepwise procedure with detergent, deionized water, acetone, and isopropanol.…”

High-performance wide bandgap perovskite solar cells fabricated in ambient high-humidity conditions

“…Inorganic-organic metal-halide perovskite solar cells (PSCs) have become the most attractive class of thin-film photovoltaic (PV) technology in the last decade, due to the astonishingly fast rise of their power conversion efficiency (PCE) values from 3.8 to 25.5% within 10 years only [1,2]. Besides, this emergent PV technology has shown enormous potential for cost savings, due to the non-vacuum low-temperature deposition and crystallization [3] of the cell layers, enabling also application on inexpensive flexible substrates [4][5][6][7][8].…”

Effect of Bathocuproine Concentration on the Photovoltaic Performance of NiOx-Based Perovskite Solar Cells

“…Perovskite solar cells possess great capabilities such as low cost, high power efficiency possessing perovskite materials with long diffusion length, high mobility, tunable band gap, low exciton binding energy, high absorption coefficient [1][2][3][4][5][6][7]. Due to the cost and energy efficient production techniques for fabrication of perovskite solar cells, they are super foreseen as competitors of silicon solar cells [8,9] and are regarded as coming alternatives of silicon-based solar cells [8,10,11].…”