Azetidinium lead iodide for perovskite solar cells

Abstract

Hybrid organic-inorganic perovskites have been established as good candidate materials for emerging photovoltaics, with device efficiencies of over 22 % being reported. There are currently only two organic cations, methylammonium and formamidinium, which produce 3D perovskites with band gaps suitable for photovoltaic devices. Numerous computational studies have identified azetidinium as a potential third cation for synthesizing organic-inorganic perovskites, but to date no experimental reports of azetidinium containing perovskites have been published. Here we prepare azetidinium lead iodide for the first time and show that it is a stable, bright orange material that can be successfully used as the absorber layer in solar cells.We also show that it is possible to make mixed cation devices by adding the azetidinium cation to methylammonium lead iodide. Mixed azetidinium-methylammonium cells show improved performance and reduced hysteresis compared to methylammonium lead iodide cells.

Partial cation substitution reduces iodide ion transport in lead iodide perovskite solar cells

“…Recent studies underline the benefits of mixing cations and/or anions in the halide perovskite structure. [6][7][8][9][10][11][12][13][14][15] In comparison to the archetypal methylammonium lead iodide (MAPbI 3 ), mixed-cation perovskites allow the band gap to be finely tuned, as well as exhibiting enhanced stability. 10 Some studies suggest there is lower current-voltage ( JV) curve hysteresis in mixed cation devices, even when all the other contact layers remain the same.…”

“…10 Some studies suggest there is lower current-voltage ( JV) curve hysteresis in mixed cation devices, even when all the other contact layers remain the same. 8,10 Mixed formamidinium (FA) and methylammonium (MA) materials form solid solutions 16 with triplecation perovskite solar cells (PSCs) fabricated by the addition of small amounts of CsI to the MA/FA mixture. Multiple cation cells have the highest efficiencies, with many examples producing over 20%, with the current record of 23.7%.…”

An Environmentally Stable Organic–Inorganic Hybrid Perovskite Containing Py Cation with Low Trap-State Density

“…Moisture stability Bad [18] Bad [31] Regular [21] Good [23] Good [25] Thermal stability Bad [34] Regular [19] Regular [35] N/A Good [9] 5. Conclusions…”

“…Most recently, ring-based molecules with a strong hydrophobic nature were considered as an alternative in replacing the conventional unstable MA molecule. In 2017 [23], a four-membered ring-based azetidine (Az) molecule was introduced into the perovskite crystal structure to form AzPbI 3 . According to the results, the AzPbI 3 exhibited excellent moisture stability.…”

A Water-Stable Organic-Inorganic Hybrid Perovskite for Solar Cells by Inorganic Passivation

“…Progress has been made to address the instability problem. Numerous computational simulations and experiments have found several promising structures such as FAPbI 3 [6] (formamidinium lead iodide), AzPbI 3 [7] (azetidinium lead iodide), and KMnF 3 [8]. Unfortunately, none of these structures offer both the desired stability and PCE.…”