Low-temperature operation of perovskite solar cells: With efficiency improvement and hysteresis-less

Methylammonium lead iodide perovskite solar cells (PSCs) based on a solution-processed ZnO electron transporting layer were systematically investigated at low-temperature operating conditions. The power conversion efficiency gradually improved from 14.2% to 15.5% as the temperature decreased from 298 to 253 K, mainly owing to increments of short circuit current density and open circuit voltage. In addition, the improvements in photocurrent related to the high charge carrier mobility, owing to the ideal non dispersive charge transport and fast electron transport lifetime at low temperature. Strikingly, hysteresis was suppressed with decreasing temperature related to the inhibition or relatively slow of ionic migration at reversed poling direction. This finding shows promising result of PSCs working efficiently under low temperature condition. (C) 2016 Elsevier Ltd. All rights reserved.