The organic-inorganic hybrid perovskite materials, especially methyl ammonium lead iodide (MAP), have garnered a huge interest of the photovoltaic community due to their insurmountable charge carrier properties.1,2 The rapid surge of the photon to current conversion efficiencies (PCE) with MAP as a light absorber, in a span of 9 years3 showed promise to bring a breakthrough in the photovoltaic technologies, due to the ease of manufacture and the low cost of fabrication, until the literature started highlighting the instability of this material. The degradation of this material stems from its limited tolerance to moisture, oxygen and light.4,5 Other than the inherent propensity of this material to degrade under ambient conditions, we have demonstrated the role of substrate in dictating the rate and product of degradation, and also devised a simple, chemical route to regenerate the degraded perovskite.6 Additionally, in an attempt to fabricate stable and robust solar cells, we have synthesized a novel hybrid compound, imidazolium lead iodide (ImP) which has the same stoichiometry ABX3 as the perovskite, but crystallographically is a hexagonal structure.7,8 We show, based on the structural analysis and our experiments, that ImP is much more stable to ambient conditions as compared to the conventional perovskite MAP and has the potential to serve as a promising candidate for photovoltaic devices.8
1. Wehrenfennig, C.; Eperon, G.; Johnston, M.; Snaith, H.; Herz, L. Advanced Materials 2013, 26, 1584-1589.
2. Motta, C.; El-Mellouhi, F.; Sanvito, S. Scientific Reports 2015, 5, 12746.
3. Park, N. The Journal of Physical Chemistry Letters 2013, 4, 2423-2429.
4. Dkhissi, Y.; Weerasinghe, H.; Meyer, S.; Benesperi, I.; Bach, U.; Spiccia, L.; Caruso, R.; Cheng, Y. Nano Energy 2016, 22, 211-222.
5. Tong, C.; Geng, W.; Tang, Z.; Yam, C.; Fan, X.; Liu, J.; Lau, W.; Liu, L. The Journal of Physical Chemistry Letters 2015, 6, 3289-3295.
6. Seth, C.; Khushalani, D. RSC Adv. 2016, 6, 101846-101852.
7. Weber, O.; Marshall, K.; Dyson, L.; Weller, M. Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 2015, 71, 668-678.
8. Seth, C.; Khushalani, D. (Manuscript under preparation)