Amino-Rich Carbon Quantum Dots Decorated Sno2 Etl with Enhanced Charge Extraction Ability and Surface Wettability Properties for Efficiency Perovskite Solar Cells

Abstract

An electron transport layer (ETL) with excellent conductivity and surface wettability properties plays a vital role in accelerating charge extraction and promoting the growth of photoactive layer for achieving highly efficient planar perovskite solar cells (PSCs). Herein, amino-rich carbon quantum dots (shortened as ACDs hereafter) with multi-roles were developed and introduced into SnO2 precursor solution to enhance the photoelectric properties of SnO2. First, the conductivity and the Fermi energy level of SnO2 were improved via electron injection by introducing ACDs, contributing to efficient charge transport and collection. Secondly, the amino functional groups on the surface of ACDs promoted the saturated growth of perovskite grain, forming high-quality photoactive layers. These outstanding properties greatly accelerated the charge extraction and reduce the trap density within the perovskite layer. As a result, the champion solar cell based on ACDs presented a power conversion efficiency of 22.02% with VOC of 1.11V.

Keywords: amino-rich carbon quantum dots, Conductivity, grain growth, Perovskite solar cells