N-Bromosuccinimide as a p-type dopant for a Spiro-OMeTAD hole transport material to enhance the performance of perovskite solar cells

Abstract

Low cost N-bromosuccinimide (NBS) was applied as an effective p-type dopant in 2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9-spirobifluorene (Spiro-OMeTAD), an important hole transport material (HTM) for perovskite solar cells (PSCs). At the optimum doping concentration, the hole mobility, conductivity, stability, and various performances of the devices were significantly improved, particularly the hole mobility increased by more than 3.5 times from 1.39 × 10⁻⁴ cm² V⁻¹ s⁻¹ to 4.92 × 10⁻⁴ cm² V⁻¹ s⁻¹. This dopant prompted the power conversion efficiency (PCE) of the PSC device from 16.12% to 19.24% (0.1 cm², AM 1.5G, 100 mW cm⁻²) with high stability.