An important property of hybrid layered perovskite is the possibility to reduce its dimensionality to provide wider band gap and better stability. In this work, 2D perovskite of the structure (PEA)2(MA)n–1PbnBr3n+1 has been sensitized, where PEA is phenyl ethyl‐ammonium, MA is methyl‐ammonium, and using only bromide as the halide. The number of the perovskite layers has been varied (n) from n = 1 through n = ∞. Optical and physical characterization verify the layered structure and the increase in the band gap. The photovoltaic performance shows higher open circuit voltage (Voc) for the quasi 2D perovskite (i.e., n = 40, 50, 60) compared to the 3D perovskite. Voc of 1.3 V without hole transport material (HTM) and Voc of 1.46 V using HTM have been demonstrated, with corresponding efficiency of 6.3% and 8.5%, among the highest reported. The lower mobility and transport in the quasi 2D perovskites have been proved effective to gain high Voc with high efficiency, further supported by ab initio calculations and charge extraction measurements. Bromide is the only halide used in these quasi 2D perovskites, as mixing halides have recently revealed instability of the perovskite structure. These quasi 2D materials are promising candidates for use in optoelectronic applications that simultaneously require high voltage and high efficiency.

Organic−inorganic perovskite structured compounds have recently emerged as attractive materials in the fields of photovoltaic due to their exciting optical properties and easy syntheses, as well as exceptional structural and optical tunability. This work presents a Dion−Jacobson two-dimensional (2D) perovskite using diammonium as the barrier molecule. We show that the diammonium barrier molecule is responsible for the perovskite layers' orientation supported by Hall Effect measurements, which results in a high efficiency solar cell for 2D perovskite without the need for additives or any additional treatment. The 2D perovskite cells achieved an efficiency of 15.6%, which was one of the highest reported for low-dimensional perovskite. Charge extraction, voltage decay, and charge collection efficiency measurements show the beneficial alignment of the 2D perovskites related to the selective contacts. Stability characterization shows that the stability for the 2D perovskite was enhanced compared with their 3D counterparts.

A power conversion efficiency of 9.5% and an open circuit voltage of more than 1.4 V were achieved for bromide-based quasi 2D perovskite solar cells.

Three‐dimensional (3 D) perovskite has attracted a lot of attention owing to its success in photovoltaic (PV) solar cells. However, one of its major crucial issues lies in its stability, which has limited its commercialization. An important property of organic–inorganic perovskite is the possibility of forming a layered material by using long organic cations that do not fit into the octahedral cage. These long organic cations act as a “barrier” that “caps” 3 D perovskite to form the layered material. Controlling the number of perovskite layers could provide a confined structure with chemical and physical properties that are different from those of 3 D perovskite. This opens up a whole new batch of interesting materials with huge potential for optoelectronic applications. This Minireview presents the synthesis, properties, and structural orientation of low‐dimensional perovskite. It also discusses the progress of low‐dimensional perovskite in PV solar cells, which, to date, have performance comparable to that of 3 D perovskite but with enhanced stability. Finally, the use of low‐dimensional perovskite in light‐emitting diodes (LEDs) and photodetectors is discussed. The low‐dimensional perovskites are promising candidates for LED devices, mainly because of their high radiative recombination as a result of the confined low‐dimensional quantum well.

Perovskite is a promising light harvester for use in photovoltaic solar cells. In recent years, the power conversion efficiency of perovskite solar cells has been dramatically increased, making them a competitive source of renewable energy. An important parameter when designing high efficiency perovskite-based solar cells is the perovskite deposition, which must be performed to create complete coverage and optimal film thickness. This paper describes an in-depth study on two-step deposition, separating the perovskite deposition into two precursors. The effects of spin velocity, annealing temperature, dipping time, and methylammonium iodide concentration on the photovoltaic performance are studied. Observations include that current density is affected by changing the spin velocity, while the fill factor changes mainly due to the dipping time and methylammonium iodide concentration. Interestingly, the open circuit voltage is almost unaffected by these parameters. Hole conductor free perovskite solar cells are used in this work, in order to minimize other possible effects. This study provides better understanding and control over the perovskite deposition through highly efficient, low-cost perovskite-based solar cells.