Enhanced photovoltaic properties of perovskite solar cells by the addition of cellulose derivatives to MAPbI3 based photoactive layer

Abstract

In this study, chlorodeoxyhydroxyethylcellulose (CDHC) was synthesized from hydroxyethylcellulose (HEC) through chlorination and then both HEC and CDHC were applied individually as additives within the methylammonium lead iodide (CH3NH3PbI3, MAPbI3) layers of perovskite solar cells (PVSCs). The architecture of the PVSCs was indium tin oxide/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate/MAPbI3:cellulose derivative/[6,6]-phenyl-C61-butyric acid methyl ester/Ag. The photovoltaic (PV) properties of the HEC- and CDHC-incorporated PVSCs were superior to those of the corresponding pristine PVSC prepared without an additive, a result of decreases in the number of grain boundary defects as well as increases in the crystal grain sizes, crystallinities, and absorption intensities of the modified perovskite films. Moreover, the polymer chains of CDHC, presenting chlorine atoms, were particularly beneficial for enhancing the crystal size and crystallinity of the MAPbI3 film, resulting in the highest absorbance and PV performance in this study being those of a CDHC-doped PVSC. Indeed, this CDHC-incorporated PVSC displayed a short-circuit current density of 17.73 mA cm−2, an open-circuit voltage of 0.96 V, a fill factor of 0.61, and a power conversion efficiency of 10.38%.