Stabilizing Perovskite Precursor by Synergy of Functional Groups for NiO_x‐Based Inverted Solar Cells with 23.5 % Efficiency

Abstract

Perovskite solar cells suffer from poor reproducibility due to the degradation of perovskite precursor solution. Herein, we report an effective precursor stabilization strategy via incorporating 3-hydrazinobenzoic acid (3-HBA) containing carboxyl (À COOH) and hydrazine (À NHNH 2 ) functional groups as stabilizer. The oxidation of I À , deprotonation of organic cations and amine-cation reaction are the main causes of the degradation of mixed organic cation perovskite precursor solution. The À NHNH 2 can reduce I 2 defects back to I À and thus suppress the oxidation of I À , while the H + generated by À COOH can inhibit the deprotonation of organic cations and subsequent amine-cation reaction. The above degradation reactions are simultaneously inhibited by the synergy of functional groups. The inverted device achieves an efficiency of 23.5 % (certified efficiency of 23.3 %) with an excellent operational stability, retaining 94 % of the initial efficiency after maximum power point tracking for 601 hours.

The Effect of Redox Reactions on the Stability of Perovskite Solar Cells

“…In addition to the above-mentioned targeted countermeasures for each reason of redox reactions, some general countermeasures have been explored. For example, the removal of I 0 defects by reduction using hypophosphorous acid (HPA) [160] and the reduction of I 2 by reacting them with 3-hydrazinobenzoic acid (3-HBA), [161] although none of these methods can guarantee the elimination of Pb 0 and I 0 defect under long-term operating conditions. In these years, Wang et al were the first to propose the concept of a redox shuttle (Eu 2 + -Eu 3 + ).…”

Surface Reconstruction for Efficient NiOx‐Based Inverted Perovskite Solar Cells

“…[2][3][4][5][6][7][8][9][10] Most importantly, compared with the conventional n-i-p PSCs, the p-i-n devices hold crucial advantages, including negligible hysteresis and superior stability, making them more attractive for commercialization. [11][12][13][14][15][16][17][18][19][20] The key factor limiting the PCE improvement is the undesirable nonradiative recombination [19,4,[21][22][23][24][25][26][27][28][29][30][31][32][33][34] which is caused by various defects in perovskite films, [35][36][37][38] and the energy level mismatch at the perovskite/charge transport layer interfaces. Especially, the perovskite surface is confirmed to harbor large amounts of defects, [39,40] which play a critical role in determining interfacial charge transport and recombination.…”

Interface passivation using choline acetate for efficient and stable planar perovskite solar cells

“…Recent developments in the eld of photovoltaic applications have received considerable attention from researchers in organic-inorganic hybrid perovskite materials due to their favorable optical band gap, high absorption coefficient, low exciton binding energy, long carrier diffusion length, and higher carrier mobility. [1][2][3][4][5][6][7] Perovskite solar cells (PSCs) have achieved a rapid rise in PCE, rising from 3.8% in 2009 to 25.7% in 2023. 8,9 This unprecedented speed of advancement marks a signicant milestone in the history of solar development.…”