Exploring the Effect of Ammonium Iodide Salts Employed in Multication Perovskite Solar Cells with a Carbon Electrode

Abstract

Perovskite solar cells that use carbon (C) as a replacement of the typical metal electrodes, which are most commonly employed, have received growing interest over the past years, owing to their low cost, ease of fabrication and high stability under ambient conditions. Even though Power Conversion Efficiencies (PCEs) have increased over the years, there is still room for improvement, in order to compete with metal-based devices, which exceed 25% efficiency. With the scope of increasing the PCE of Carbon based Perovskite Solar Cells (C-PSCs), in this work we have employed a series of ammonium iodides (ammonium iodide, ethylammonium iodide, tetrabutyl ammonium iodide, phenethylammonium iodide and 5-ammonium valeric acid iodide) as additives in the multiple cation-mixed halide perovskite precursor solution. This has led to a significant increase in the PCE of the corresponding devices, by having a positive impact on the photocurrent values obtained, which exhibited an increase exceeding 20%, from 19.8 mA/cm2, for the reference perovskite, to 24 mA/cm2, for the additive-based perovskite. At the same time, the ammonium iodide salts were used in a post-treatment method. By passivating the defects, which provide charge recombination centers, an improved performance of the C-PSCs has been achieved, with enhanced FF values reaching 59%, which is a promising result for C-PSCs, and Voc values up to 850 mV. By combining the results of these parallel investigations, C-PSCs of the triple mesoscopic structure with a PCE exceeding 10% have been achieved, while the in-depth investigation of the effects of ammonium iodides in this PSC structure provide a fruitful insight towards the optimum exploitation of interface and bulk engineering, for high efficiency and stable C-PSCs, with a structure that is favorable for large area applications.

Enhancing Photostability of Complex Lead Halides through Modification with Antibacterial Drug Octenidine

“…All the Oct(A) n−1 Pb n I 3n+1 (where A = FA, Cs 0.12 FA 0.88 and A = Cs 0.1 MA 0.15 FA 0.75 ) films exhibit the APbI 3 perovskite cubic phase peaks corresponding to the (001), (011), (111), (002), (012), (022), and (003) diffraction planes, respectively [ 87 ]. However, virtually all Oct(A) n−1 Pb n I 3n+1 films reveal the additional peak at 7.6°, which can be attributed to the formation of 2D perovskite phase coexisting with the 3D perovskite phase [ 88 , 89 ]. The emergence of additional peaks at around 2θ = 12° and 26.5° for the material formulations with A = FA and Cs 0.12 FA 0.88 is attributed to the formation of quasi-3D perovskites Oct(A) n−1 Pb n I 3n+1 (where n > 10) [ 90 , 91 , 92 ].…”

Interface Effects on the Stability of Carbon‐Electrode‐Based Perovskite Solar Cells During Damp Heating

“…[10,16,[25][26][27] This perovskite is also known to develop a better contact surface with TiO 2 with a lower defect concentration. [28][29][30][31] However, the combination of the AVAI additive and the HTL-free device configuration, along with a thick zirconia buffer layer, can leads to a strong hysteresis behavior together with a "bump" patterned observed in the reverse J-V scan. [8,[32][33][34] To address this issue, different strategies have been scouted in literature to enhance charge extraction and transfer.…”

Maturing Effects in Carbon‐Based Perovskite Solar Cells: Understanding and Consequences on Photovoltaic Performances

“…This PK is also known to develop a better contact surface with TiO 2 with a lower defect concentration. [21][22][23][24] The introduction of this AVAI additive coupled to the HTM-free device configuration having a thick zirconia buffer layer however seems to induce a large hysteresis behavior as well as the appearance of a "bump" in the reverse J-V scan. [9,[25][26][27] To address this problem, different strategies have been used in literature such as the addition of CuSCN, [27,28] a well-known inorganic hole transport material, to the PK solution allowing to form of a bulk heterojunction.…”