N-Bromosuccinimide as an Interfacial Alleviator for Br/I Exchange in Perovskite for Solar Cell Fabrication

Abstract

Engineering the surface at the rear interface between the perovskite and the hole transporting material is of paramount importance to minimize non-radiative losses. We report the use of Nbromosuccinimide (NBS), as an interfacial alleviator to influence crystallization of the perovskite and defect passivation. The NBS treatment promotes added charge extraction and yields devices with improved photovoltaic performance. Thus formed perovskite layers exhibit grain size increment and lowered trap density. An improved device performance was noted with an optimized concentration of 0.5% NBS as compared to pristine perovskite due to the open circuit voltage and short circuit current density enhancement. The coordination of bromide influences the crystal lattice as shown by polarization modulated-infrared reflectionabsorption spectroscopy, which in turn may influence charge transport and interfacial properties.

An Approach to Quantify the Negative Capacitance Features in a Triple‐Cation based Perovskite Solar Cells

“…The selective contact/perovskite interfaces play a pivotal role in controlling the mechanisms of the charge extraction capability, accumulation, and recombination. Therefore, knowledge and understanding of the physical processes taking place in the bulk and interfacial layers are of utmost interest to intensely comprehend PSCs peculiarities for the pursuit of performance enhancement [17]. Toward this end, several methods have been used to probe correlated charge carrier kinetics in PSCs including low-frequency noise (LFN) [18], opencircuit voltage decay measurements [19], photocurrent spectroscopy [20], and electrochemical impedance spectroscopy (EIS) [21].…”

“…Therefore, knowledge and understanding of the physical processes taking place in the bulk and interfacial layers are of utmost interest to intensely comprehend PSCs peculiarities for the pursuit of performance enhancement. [17] Toward this end, several methods have been used to probe correlated charge carrier kinetics in PSCs including low-frequency noise (LFN), [18] open-circuit voltage decay measurements, [19] photocurrent spectroscopy, [20] and electrochemical impedance spectroscopy (EIS). [21] EIS provides information regarding the electrical response (resistive and capacitive processes) on different timescales with high sensitivity.…”

Tetra-indole core as a dual agent: a hole selective layer that passivates defects in perovskite solar cells

“…The build-in potential (Vbi) and depletion layer width (W) was derived from C -2 -V plot. 55,56 An improved build in potential of 740 mV for the TTI treated PSC was extracted, at 10 kHz, while the pristine PSC gave a value of 734 mV. The calculated Vbi value for TTI treated device is slightly higher as compared to the untreated one, which ascribes enhanced charge extraction and high photocurrent.…”

Reducing the Trap Density in MAPbI3 Based Perovskite Solar Cells via Bromide Substitution

“…Owing to the presence of optimal bromide content in the perovskite precursor, enhanced “shelf‐life” of the devices via bromide doping in the perovskite solution in both light and dark conditions at ambient air was reported [27] . The role of NBS as a bromide precursor in (MAPbBr 3 ) 0.15 (FAPbI 3 ) 0.85 was found to be beneficial in terms of reducing the surface defects and improving stability [28] . We demonstrated an effective strategy to construct polycrystalline perovskite thin films with low surface roughness, and increment in grain size.…”