Increased Efficiency for Perovskite Photovoltaics via Doping the PbI2 Layer
journal contributionposted on 12.10.2016, 00:00 by Sally Mabrouk, Ashish Dubey, Wenfeng Zhang, Nirmal Adhikari, Behzad Bahrami, Md Nazmul Hasan, Shangfeng Yang, Qiquan Qiao
Perovskite solar cells offer tremendous potential for simple and low-cost solution-based fabrication with high power conversion efficiency. This work focused on adding an optimized amount of additive tetra-n-butylammonium triiodide (TBAI3) into the precursor PbI2 layer to improve the performance of perovskite solar cells. UV–vis absorption spectra exhibited an enhancement in the absorbance of perovskite films while AFM images showed smoother MAPbI3 film after adding TBAI3. X-ray diffraction (XRD) measurements indicated that TBAI3 acted as a polar Lewis base, forming an adduct with the Lewis acid Pb2+, increasing PbI2 solubility, and enhancing crystal growth of perovskite. Current density–voltage (J–V) characteristics and transient photocurrent measurements showed that the TBAI3 dopant achieved an increase in short circuit current density (Jsc) and open circuit voltage (Voc) and a decrease in the charge transport time compared to the reference cell without any additive. Perovskite solar cell efficiency was enhanced from 11.18% to 14.85% by adding TBAI3 dopant to the PbI2 precursor.