Multidentate Chelation Heals Structural Imperfections for Minimized Recombination Loss in Lead‐Free Perovskite Solar Cells

Abstract

Tin-based perovskite solar cells (Sn-PSCs) have emerged as promising environmentally viable photovoltaic technologies, but still suffer from severe non-radiative recombination loss due to the presence of abundant deep-level defects in the perovskite film and under-optimized carrier dynamics throughout the device. Herein, we healed the structural imperfections of Sn perovskites in an "inside-out" manner by incorporating a new class of biocompatible chelating agent with multidentate claws, namely, 2-Guanidinoacetic acid (GAA), which passivated a variety of deep-level Snrelated and I-related defects, cooperatively reinforced the passivation efficacy, released the lattice strain, improved the structural toughness, and promoted the carrier transport of Sn perovskites. Encouragingly, an efficiency of 13.7 % with a small voltage deficit of � 0.47 V has been achieved for the GAA-modified Sn-PSCs. GAA modification also extended the lifespan of Sn-PSCs over 1200 hours.

A vertical antioxidant strategy for high performance wide band gap tin perovskite photovoltaics

“…S7–S9†). 12,29 As depicted in Fig. 2b, the content of Sn 4+ on the surface of the pristine is relatively high and still large at the film inside, which is 37.8%, 35.1%, and 31.4%, respectively, with the increase of sputtering time.…”

A trifunctional polyethylene oxide buffer layer for stable and efficient all-inorganic CsPbBr3perovskite solar cells

“…These are beneficial for shortening the carrier transport path. 24,25 Hence, their alignment minimizes the charge carrier transport length and therefore maximizes the carrier transport efficiency. Fig.…”

Constructing spike-like energy band alignment at the heterointerface in highly efficient perovskite solar cells

“…The incorporation of organic molecules containing N-, S-, or O-donors has been universally acknowledged to show peculiarities in boosting efficiency and stability based on Lewis acid-base chemistry. [21][22][23][24][25][26][27][28][29][30] Recently, Hagfeldt et al discovered that a dipolar interlayer of azetidinium lead iodide (AzPbI 3 ) could increase device performance. 31 Yang et al found that tailoring the dipolar molecules to induce an extra electric eld at the heterointerface can improve the performance and stability of the device.…”